This table will no longer be updated after 5/30/2024 given the end of the 2023-2024 viral respiratory vaccine season.

This table shows the cumulative number and percentage of CT residents who have received an updated COVID-19 vaccine during the 2023-2024 viral respiratory season by age group (current age).
CDC recommends that people get at least one dose of this vaccine to protect against serious illness, whether or not they have had a COVID-19 vaccination before. Children and people with moderate to severe immunosuppression might be recommended more than one dose. For more information on COVID-19 vaccination recommendations, click here.
• Data are reported weekly on Thursday and include doses administered to Saturday of the previous week (Sunday – Saturday). All data in this report are preliminary. Data from the previous week may be changed because of delays in reporting, deduplication, or correction of errors.
• These analyses are based on data reported to CT WiZ which is the immunization information system for CT. CT providers are required by law to report all doses of vaccine administered. CT WiZ also receives records on CT residents vaccinated in other jurisdictions and by federal entities which share data with CT Wiz electronically. Electronic data exchange is being added jurisdiction-by-jurisdiction. Currently, this includes Rhode Island and New York City but not Massachusetts and New York State. Therefore, doses administered to CT residents in neighboring towns in Massachusetts and New York State will not be included. A full list of the jurisdiction with which CT has established electronic data exchange can be seen at the bottom of this page (https://portal.ct.gov/immunization/Knowledge-Base/Articles/Vaccine-Providers/CT-WiZ-for-Vaccine-Providers-and-Training/Query-and-Response-functionality-in-CT-WiZ?language=en_US)
• Population size estimates used to calculate cumulative percentages are based on 2020 DPH provisional census estimates*.
• People are included if they have an active jurisdictional status in CT WiZ at the time weekly data are pulled. This excludes people who live out of state, are deceased and a small percentage who have opted out of CT WiZ.
* DPH Provisional State and County Characteristics Estimates April 1, 2020. Hayes L, Abdellatif E, Jiang Y, Backus K (2022) Connecticut DPH Provisional April 1, 2020, State Population Estimates by 18 age groups, sex, and 6 combined race and ethnicity groups. Connecticut Department of Public Health, Health Statistics & Surveillance, SAR, Hartford, CT.

Data on vaccination and exemption rates from school immunization surveys of childcare/preschool, kindergarten, grade 7, grade 11, and college.

Morocco MA: Immunization: DPT: % of Children Aged 12-23 Months data was reported at 99.000 % in 2016. This stayed constant from the previous number of 99.000 % for 2015. Morocco MA: Immunization: DPT: % of Children Aged 12-23 Months data is updated yearly, averaging 94.000 % from Dec 1982 (Median) to 2016, with 35 observations. The data reached an all-time high of 99.000 % in 2016 and a record low of 32.000 % in 1982. Morocco MA: Immunization: DPT: % of Children Aged 12-23 Months data remains active status in CEIC and is reported by World Bank. The data is categorized under Global Database’s Morocco – Table MA.World Bank: Health Statistics. Child immunization, DPT, measures the percentage of children ages 12-23 months who received DPT vaccinations before 12 months or at any time before the survey. A child is considered adequately immunized against diphtheria, pertussis (or whooping cough), and tetanus (DPT) after receiving three doses of vaccine.; ; WHO and UNICEF (http://www.who.int/immunization/monitoring_surveillance/en/).; Weighted average;

Morocco MA: Immunization: HepB3: % of One-Year-Old Children data was reported at 99.000 % in 2016. This stayed constant from the previous number of 99.000 % for 2015. Morocco MA: Immunization: HepB3: % of One-Year-Old Children data is updated yearly, averaging 96.500 % from Dec 1999 (Median) to 2016, with 18 observations. The data reached an all-time high of 99.000 % in 2016 and a record low of 10.000 % in 1999. Morocco MA: Immunization: HepB3: % of One-Year-Old Children data remains active status in CEIC and is reported by World Bank. The data is categorized under Global Database’s Morocco – Table MA.World Bank: Health Statistics. Child immunization rate, hepatitis B is the percentage of children ages 12-23 months who received hepatitis B vaccinations before 12 months or at any time before the survey. A child is considered adequately immunized after three doses.; ; WHO and UNICEF (http://www.who.int/immunization/monitoring_surveillance/en/).; Weighted average;

BackgroundMpox (monkeypox) infection has become a global concern for healthcare authorities after spreading in multiple non-endemic countries. Following the sudden multi-country outbreak of Mpox, the World Health Organization (WHO) declared a public health emergency of international concern. We do not have any vaccines approved for the prevention of Mpox infection. Therefore, international healthcare authorities endorsed smallpox vaccines for the prevention of Mpox disease. Here we intended to perform this cross-sectional study among the adult males in Bangladesh to assess the Mpox vaccine perception and vaccination intention.MethodsWe conducted this web-based survey among the adult males in Bangladesh from September 1, 2022, to November 30, 2022, using Google Forms. We assessed the Mpox vaccine perception and vaccination intention. We performed a chi-square test to compare vaccine perception and vaccination intention levels. Also, we performed multiple logistic regression analyses to determine the association between the study parameters and the sociodemographic profile of the participants.ResultsAccording to the present study, the Mpox vaccine perception was high among 60.54% of the respondents. Also, 60.05% of respondents showed medium vaccination intention. Mpox vaccine perception and vaccination intention were strongly associated with the sociodemographic profiles of the participants. Furthermore, we discovered a significant association between the level of education and vaccination intention among the respondents. Also, age and marital status played a role in the Mpox vaccine perception and vaccination intention.ConclusionOur findings showed a significant association between sociodemographic characteristics and the Mpox vaccine perception/vaccination intention. Along with the country’s long experience in mass immunization, campaigns about Covid-19 vaccines and high vaccination rates might play a role in Mpox vaccine perception and vaccination intention. We recommend more social awareness and educational communications or seminars for the target population to bring more positive changes in their attitude towards Mpox prevention.

BackgroundThe World Health Organization (WHO) recommends oral cholera vaccines (OCVs) as a supplementary tool to conventional prevention of cholera. Dukoral, a killed whole-cell two-dose OCV, was used in a mass vaccination campaign in 2009 in Zanzibar. Public and private costs of illness (COI) due to endemic cholera and costs of the mass vaccination campaign were estimated to assess the cost-effectiveness of OCV for this particular campaign from both the health care provider and the societal perspective. Methodology/Principal FindingsPublic and private COI were obtained from interviews with local experts, with patients from three outbreaks and from reports and record review. Cost data for the vaccination campaign were collected based on actual expenditure and planned budget data. A static cohort of 50,000 individuals was examined, including herd protection. Primary outcome measures were incremental cost-effectiveness ratios (ICER) per death, per case and per disability-adjusted life-year (DALY) averted. One-way sensitivity and threshold analyses were conducted. The ICER was evaluated with regard to WHO criteria for cost-effectiveness. Base-case ICERs were USD 750,000 per death averted, USD 6,000 per case averted and USD 30,000 per DALY averted, without differences between the health care provider and the societal perspective. Threshold analyses using Shanchol and assuming high incidence and case-fatality rate indicated that the purchase price per course would have to be as low as USD 1.2 to render the mass vaccination campaign cost-effective from a health care provider perspective (societal perspective: USD 1.3). Conclusions/SignificanceBased on empirical and site-specific cost and effectiveness data from Zanzibar, the 2009 mass vaccination campaign was cost-ineffective mainly due to the relatively high OCV purchase price and a relatively low incidence. However, mass vaccination campaigns in Zanzibar to control endemic cholera may meet criteria for cost-effectiveness under certain circumstances, especially in high-incidence areas and at OCV prices below USD 1.3.

Mass vaccination clinics efficiently vaccinate large numbers of people. The CARD system (Comfort, Ask, Relax, Distract) is a vaccination delivery framework that can improve the experiences of vaccine recipients and providers. This two-stage hybrid effectiveness-implementation study implemented and sustained CARD in university-based vaccination clinics involving pharmacy student vaccinators. Stage 1 was a before-and-after study conducted across four COVID-19 vaccination clinics in November-December, 2022. Stage 2 was a single cohort study whereby CARD was sustained across four COVID-19/influenza vaccination clinics in November, 2023. In both stages, vaccine recipients rated experiences relative to last vaccination (primary outcome) and symptoms (pain, fear, dizziness) using surveys. Pharmacy student vaccinators completed attitudes and behaviors surveys; a subsample participated in focus groups. In Stage 1, more vaccine recipients in the after period (vs. before) reported a better vaccination experience relative to their last vaccination (64.0% vs 33.6%; p 

This open dataset shows data on Cambridge residents who have received a COVID-19 vaccine at any location (e.g., mass vaccination site, pharmacy, doctor's office). These data come from the Massachusetts Department of Public Health's weekly report on vaccine doses administered by municipality. The report is released on Thursdays.
The Moderna and Pfizer vaccines require two doses administered at least 28 days apart in order to be fully vaccinated. The J&J (Janssen) vaccine requires a single dose in order to be fully vaccinated.
The category "Residents Who Received at Least One Dose" reflects the total number of individuals in the fully and partially vaccinated categories. That is, this category comprises individuals who have received one or both doses of the Moderna/Pfizer vaccine or have received the single dose J&J (Janssen) vaccine.
The category "Fully Vaccinated Residents" comprises individuals who have received both doses of the Moderna/ Pfizer vaccine or the single-dose J&J vaccine.
The category "Partially Vaccinated Residents" comprises individuals who have received only the first dose of the Moderna/Pfizer vaccine.
Source: Weekly COVID-19 Municipality Vaccination Report. Massachusetts releases updated data each Thursday at 5 p.m.

IntroductionSince 2010, WHO has recommended oral cholera vaccines as an additional strategy for cholera control. During a cholera episode, pregnant women are at high risk of complications, and the risk of fetal death has been reported to be 2–36%. Due to a lack of safety data, pregnant women have been excluded from most cholera vaccination campaigns. In 2012, reactive campaigns using the bivalent killed whole-cell oral cholera vaccine (BivWC), included all people living in the targeted areas aged ≥1 year regardless of pregnancy status, were implemented in Guinea. We aimed to determine whether there was a difference in pregnancy outcomes between vaccinated and non-vaccinated pregnant women.Methods and FindingsFrom 11 November to 4 December 2013, we conducted a retrospective cohort study in Boffa prefecture among women who were pregnant in 2012 during or after the vaccination campaign. The primary outcome was pregnancy loss, as reported by the mother, and fetal malformations, after clinical examination. Primary exposure was the intake of the BivWC vaccine (Shanchol) during pregnancy, as determined by a vaccination card or oral history. We compared the risk of pregnancy loss between vaccinated and non-vaccinated women through binomial regression analysis. A total of 2,494 pregnancies were included in the analysis. The crude incidence of pregnancy loss was 3.7% (95%CI 2.7–4.8) for fetuses exposed to BivWC vaccine and 2.6% (0.7–4.5) for non-exposed fetuses. The incidence of malformation was 0.6% (0.1–1.0) and 1.2% (0.0–2.5) in BivWC-exposed and non-exposed fetuses, respectively. In both crude and adjusted analyses, fetal exposure to BivWC was not significantly associated with pregnancy loss (adjusted risk ratio (aRR = 1.09 [95%CI: 0.5–2.25], p = 0.818) or malformations (aRR = 0.50 [95%CI: 0.13–1.91], p = 0.314).ConclusionsIn this large retrospective cohort study, we found no association between fetal exposure to BivWC and risk of pregnancy loss or malformation. Despite the weaknesses of a retrospective design, we can conclude that if a risk exists, it is very low. Additional prospective studies are warranted to add to the evidence base on OCV use during pregnancy. Pregnant women are particularly vulnerable during cholera episodes and should be included in vaccination campaigns when the risk of cholera is high, such as during outbreaks.

Post-vaccine monitoring programs for human papillomavirus (HPV) have been introduced in many countries, but HPV serology is still an underutilized tool, partly owing to the weak antibody response to HPV infection. Changes in antibody levels among non-vaccinated individuals could be employed to monitor herd effects of immunization against HPV vaccine types 16 and 18, but inference requires an appropriate statistical model. The authors developed a four-component bivariate mixture model for jointly estimating vaccine-type seroprevalence from correlated antibody responses against HPV16 and -18 infections. This model takes account of the correlation between HPV16 and -18 antibody concentrations within subjects, caused e.g. by heterogeneity in exposure level and immune response. The model was fitted to HPV16 and -18 antibody concentrations as measured by a multiplex immunoassay in a large serological survey (3,875 females) carried out in the Netherlands in 2006/2007, before the introduction of mass immunization. Parameters were estimated by Bayesian analysis. We used the deviance information criterion for model selection; performance of the preferred model was assessed through simulation. Our analysis uncovered elevated antibody concentrations in doubly as compared to singly seropositive individuals, and a strong clustering of HPV16 and -18 seropositivity, particularly around the age of sexual debut. The bivariate model resulted in a more reliable classification of singly and doubly seropositive individuals than achieved by a combination of two univariate models, and suggested a higher pre-vaccine HPV16 seroprevalence than previously estimated. The bivariate mixture model provides valuable baseline estimates of vaccine-type seroprevalence and may prove useful in seroepidemiologic assessment of the herd effects of HPV vaccination.

NO LONGER UPDATED. See the State Respiratory Illness Reporting site (https://www.mass.gov/info-details/respiratory-illness-reporting) for more recent information.

This is a dataset for the City of Somerville Infectious Illness Dashboard. This dataset combines multiple public data sources concerning COVID and flu in Massachusetts and, where possible, in the Somerville area specifically. Data sources include the Center for Disease Control, the Massachusetts Department of Public Health, and the Massachusetts Water Resources Authority.

United States SB: MA: COVID Test/Vaccine: Proof of COVID Vaccination: No data was reported at 77.600 % in 11 Apr 2022. This records an increase from the previous number of 73.900 % for 04 Apr 2022. United States SB: MA: COVID Test/Vaccine: Proof of COVID Vaccination: No data is updated weekly, averaging 72.700 % from Nov 2021 (Median) to 11 Apr 2022, with 18 observations. The data reached an all-time high of 77.600 % in 11 Apr 2022 and a record low of 65.500 % in 03 Jan 2022. United States SB: MA: COVID Test/Vaccine: Proof of COVID Vaccination: No data remains active status in CEIC and is reported by U.S. Census Bureau. The data is categorized under Global Database’s United States – Table US.S049: Small Business Pulse Survey: by State: Northeast Region: Weekly, Beg Monday (Discontinued).

United States SB: MA: COVID Test/Vaccine: Proof of COVID Vaccination: N/A data was reported at 13.200 % in 11 Apr 2022. This records a decrease from the previous number of 14.100 % for 04 Apr 2022. United States SB: MA: COVID Test/Vaccine: Proof of COVID Vaccination: N/A data is updated weekly, averaging 14.050 % from Nov 2021 (Median) to 11 Apr 2022, with 18 observations. The data reached an all-time high of 19.100 % in 14 Mar 2022 and a record low of 9.000 % in 22 Nov 2021. United States SB: MA: COVID Test/Vaccine: Proof of COVID Vaccination: N/A data remains active status in CEIC and is reported by U.S. Census Bureau. The data is categorized under Global Database’s United States – Table US.S049: Small Business Pulse Survey: by State: Northeast Region: Weekly, Beg Monday (Discontinued).

We study the repertoire of immunoglobulin sequences after immunization in a cohort of rats. Animals were immunized with dinitrophenol modified KLH or with recombinant human HuD. In the immune repertoire, and also in the matching proteomics data, we observe that the animals produce a repertoire that has many shared motifs for those immunized with the same antigen. Cluster analysis allows the samples to be segregated according to the immunogen used.

The following dashboards provide data on contagious respiratory viruses, including acute respiratory diseases, COVID-19, influenza (flu), and respiratory syncytial virus (RSV) in Massachusetts. The data presented here can help track trends in respiratory disease and vaccination activity across Massachusetts.

Transdermal Microneedle Vaccine Patches Market Outlook

According to our latest research, the global Transdermal Microneedle Vaccine Patches market size reached USD 1.22 billion in 2024, demonstrating robust momentum driven by technological advancements and increasing demand for painless, efficient vaccination methods. The market is projected to expand at a CAGR of 13.7% from 2025 to 2033, reaching a forecasted value of USD 4.01 billion by 2033. This growth is propelled by rising prevalence of infectious diseases, escalating immunization programs, and heightened interest in self-administered healthcare solutions worldwide.

One of the primary growth drivers for the Transdermal Microneedle Vaccine Patches market is the increasing adoption of minimally invasive drug delivery platforms. Traditional vaccination methods, while effective, often encounter resistance due to needle phobia, risk of needle-stick injuries, and logistical challenges in mass immunization settings. Microneedle patches offer a painless, user-friendly alternative that can be self-administered, reducing the reliance on trained healthcare professionals and minimizing the risk of cross-contamination. This innovation is particularly valuable in resource-limited settings and during pandemics, where rapid, large-scale deployment of vaccines is critical. The ease of storage and transportation of these patches, often at room temperature, further enhances their appeal, especially in regions with inadequate cold chain infrastructure.

Another significant factor fueling market expansion is the continuous advancement in microneedle patch technology. Manufacturers are investing heavily in research and development to improve the efficacy, stability, and versatility of these patches. The emergence of dissolvable and coated microneedle patches enables the delivery of a broader range of vaccines, including those for emerging infectious diseases and complex therapeutic targets such as cancer and allergies. Partnerships between biotechnology firms, academic institutions, and governmental organizations are accelerating the pace of innovation, resulting in more effective and safer products. Moreover, regulatory bodies are increasingly providing clear guidelines and fast-track approvals for novel vaccine delivery systems, facilitating smoother market entry and adoption.

The rising global burden of infectious diseases and the ongoing need for mass immunization campaigns are also pivotal in shaping the Transdermal Microneedle Vaccine Patches market. The COVID-19 pandemic underscored the necessity for scalable, accessible, and safe vaccination strategies. Microneedle patches, with their potential for self-administration and reduced medical waste, align perfectly with these requirements. Additionally, the growing elderly population, who often experience difficulties with conventional injections, are likely to benefit significantly from microneedle vaccine patches. Public health initiatives and non-governmental organizations are increasingly advocating for the adoption of these patches to improve immunization coverage, particularly in remote and underserved communities.

From a regional perspective, North America currently dominates the Transdermal Microneedle Vaccine Patches market, owing to high healthcare expenditure, advanced R&D infrastructure, and proactive government support for innovative vaccine delivery technologies. However, the Asia Pacific region is anticipated to register the fastest CAGR during the forecast period, driven by large population bases, increasing awareness about vaccination, and expanding healthcare access. Europe remains a significant contributor, with strong regulatory frameworks and rising investments in biotechnology. Latin America and the Middle East & Africa are gradually embracing microneedle technology, spurred by international collaborations and efforts to improve immunization rates.

Product Type Analysis

The Product Type segment of the Trans

BackgroundThe Latin American and Caribbean (LAC) region has been one of the regions most affected by the COVID-19 pandemic, with countries presenting some of the highest numbers of cases and deaths from this disease in the world. Despite this, vaccination intention is not homogeneous in the region, and no study has evaluated the influence of the mass media on vaccination intention. The objective of this study was to evaluate the association between the use of mass media to learn about COVID-19 and the non-intention of vaccination against COVID-19 in LAC countries.MethodsAn analysis of secondary data from a Massachusetts Institute of Technology (MIT) survey was conducted in collaboration with Facebook on people's beliefs, behaviors, and norms regarding COVID-19. Crude and adjusted prevalence ratios (aPR) with their respective 95% confidence intervals (95%CI) were calculated to evaluate the association between the use of mass media and non-vaccination intention using generalized linear models of the Poisson family with logarithmic link.ResultsA total of 350,322 Facebook users over the age of 18 from LAC countries were included. 50.0% were men, 28.4% were between 18 and 30 years old, 41.4% had a high school education level, 86.1% lived in the city and 34.4% reported good health condition. The prevalence of using the mass media to learn about COVID-19 was mostly through mixed media (65.8%). The non-intention of vaccination was 10.8%. A higher prevalence of not intending to be vaccinated against COVID-19 was found in those who used traditional media (aPR = 1.36; 95%CI: 1.29–1.44; p < 0.001) and digital media (aPR = 1.70; 95%CI: 1.24–2.33; p = 0.003) compared to those using mixed media.ConclusionWe found an association between the type of mass media used to learn about COVID-19 and the non-intention of vaccination. The use of only traditional or digital information sources were associated with a higher probability of non-intention to vaccinate compared to the use of both sources.

It is urgently needed to update the comprehensive analysis about the efficacy or effectiveness of COVID-19 vaccines especially during the COVID-19 pandemic caused by SARS-CoV-2 Delta and Omicron variants. In general, the current COVID-19 vaccines showed a cumulative efficacy of 66.4%, 79.7%, and 93.6% to prevent SARS-CoV-2 infection, symptomatic COVID-19, and severe COVID-19, respectively, but could not prevent the asymptomatic infection of SARS-CoV-2. Furthermore, the current COVID-19 vaccines could effectively prevent COVID-19 caused by the Delta variant although the incidence of breakthrough infection of the SARS-CoV-2 Delta variant increased when the intervals post full vaccination extended, suggesting the waning effectiveness of COVID-19 vaccines. In addition, one-dose booster immunization showed an effectiveness of 74.5% to prevent COVID-19 caused by the Delta variant. However, current COVID-19 vaccines could not prevent the infection of Omicron sub-lineage BA.1.1.529 and had about 50% effectiveness to prevent COVID-19 caused by Omicron sub-lineage BA.1.1.529. Furthermore, the effectiveness was 87.6% and 90.1% to prevent severe COVID-19 and COVID-19-related death caused by Omicron sub-lineage BA.2, respectively, while one-dose booster immunization could enhance the effectiveness of COVID-19 vaccines to prevent the infection and COVID-19 caused by Omicron sub-lineage BA.1.1.529 and sub-lineage BA.2. Two-dose booster immunization showed an increased effectiveness of 81.8% against severe COVID-19 caused by the Omicron sub-lineage BA.1.1.529 variant compared with one-dose booster immunization. The effectiveness of the booster immunization with RNA-based vaccine BNT162b2 or mRNA-1273 was over 75% against severe COVID-19 more than 17 weeks after booster immunization whereas the heterogenous booster immunization showed better effectiveness than homologous booster immunization. In summary, the current COVID-19 vaccines could effectively protect COVID-19 caused by Delta and Omicron variants but was less effective against Omicron variant infection. One-dose booster immunization could enhance protection capability, and two-dose booster immunization could provide additional protection against severe COVID-19.

Tabulated individual data points for data reported in the associated publication: Spackman E, Suarez DL, Lee CW, Pantin-Jackwood MJ, Lee SA, Youk S, Ibrahim S. Efficacy of inactivated and RNA particle vaccines against a North American Clade 2.3.4.4b H5 highly pathogenic avian influenza virus in chickens. Vaccine. 2023 Nov 30;41(49):7369-7376. doi: 10.1016/j.vaccine.2023.10.070. Epub 2023 Nov 4. PMID: 37932132.Description of methodsVirusesThe highly pathogenic avian influenza virus (HPAIV) isolate A/turkey/Indiana/22-003707-003/2022 H5N1 (TK/IN/22) and A/Gyrfalcon/Washington/41088/2014 H5N8 (GF/WA/14) isolate were each propagated and titrated in embryonating specific pathogen free (SPF) chicken eggs using standard procedures and titers were determined using the Reed-Muench method.VaccinesAn in-house vaccine was produced by de novo synthesizing the HA gene of TK/IN/22 that was modified to be low pathogenic (LP) and placing it in a PR8 backbone using rg methods as described . The vaccine (SEP-22-N9) contained 6 genes from PR8 and a de novo synthesized N9 NA from A/blue winged teal/Wyoming/AH0099021/2016 (H7N9). The rg virus was inactivated by treatment with 0.1% beta-propiolactone. Vaccines were produced with Montanide ISA 71 VG (Seppic Inc., Fairfield, NJ) adjuvant at ambient temperature in a L5M-A high shear mixer (Silverson Machines, Inc., East Longmeadow, MA) for 30sec at 1,000rpm, then for 3min at 4,000rpm using an emulsifying screen in accordance with the adjuvant manufacturer’s instructions.Sham vaccine was prepared in-house using sterile phosphate buffered saline as described above.Commercial vaccines were supplied by the manufacturers. The commercial inactivated vaccine (1057.R1 serial 590088) (rgH5N1) (Zoetis Inc., Parsippany, NJ) was produced with the GF/WA/14 (clade 2.3.4.4c HA gene) and the remaining 7 gene segments including the NA from PR8 (1). The Sequivity vaccine (serial V040122NCF) (RP) (Merck and Co. Inc., Rahway, NJ) is an updated version of their replication restricted alphavirus vector vaccine that expresses the TK/IN/22 H5 HA (modified to be low pathogenic LP).Challenge study designThree-week-old, mixed sex, SPF white leghorn chickens (Gallus gallus domesticus) were obtained from in-house flocks and were randomly assigned to vaccine groups.All vaccines were administered by the subcutaneous route at the nape of the neck. Commercial vaccines were given at the volumes instructed by the manufacturer (0.5ml each). In-house vaccine was given at a dose of 512 hemagglutination units per bird in 0.5ml. Three weeks post vaccination chickens were challenged with 6.7 log10 50% egg infectious doses (EID50) of TK/IN/22 in 0.1ml by the intrachoanal route.Oropharyngeal (OP) and cloacal (CL) swabs were collected from all birds at 2-, 4-, and 7-days post challenge (DPC). Swabs were also collected from dead and euthanized sham vaccinates at 1DPC.To evaluate antibody-based DIVA-VI tests, blood for serum was collected from the RP and SEP-22-N9 vaccinated groups at 7, 10 and 14DPC because the SEP-22-N9 vaccine does not elicit antibodies to N1 and the RP vaccine does not elicit antibodies to the N1 or NP proteins.Mortality and morbidity were recorded for 14DPC after which time the remaining birds were euthanized. If birds were severely lethargic or had neurological signs they were euthanized and were counted as mortality at the next observation time for mean death time calculations.Evaluation of antibody titers based on prime-boost order with the RP and inactivated vaccinesTo determine if there was a difference in antibody levels based on the order of vaccination with the RP vaccine and an inactivated vaccine, groups of 20 chickens (hatch-mates of the chickens in the challenge study) were given one dose of each vaccine three weeks apart (Supplementary Table 1). The first dose was administered at three weeks of age using the RP or SEP-22-N9 vaccine as described above. Then a second dose of either the same vaccine or the other vaccine was administered three weeks later (six weeks of age). All birds were bled for serum three weeks after the second vaccination (nine weeks of age). Antibody was quantified by hemagglutination inhibition (HI) assay as described below using the homologous antigen (TK/IN/22).Quantitative rRT-PCR (qRRT-PCR)RNA was extracted from OP and CL swabs using the MagMax (Thermo Fisher Scientific, Waltham, MA) magnetic bead extraction kit with the modifications described by Das et al., (2). Quantitative real-time RT-PCR was conducted as described previously (3) on a QuantStudio 5 (Thermo Fisher Scientific). A standard curve was generated from a titrated stock of TK/IN/22 and was used to calculate titer equivalents using the real time PCR instrument’s software.Hemagglutination inhibition assayHemagglutination inhibition assays were run in accordance with standard procedures. All pre-challenge sera were tested against the challenge virus. Sera from birds vaccinated with the rgH5N1 vaccine were also tested against the vaccine antigen, GF/WA/14. Titers of 8 or below were considered non-specific binding, therefore negative.Commercial ELISAPre-vaccination sera from 30 chickens were tested to confirm the absence of antibodies to AIV with a commercial AIV antibody ELISA (IDEXX laboratories, Westbrook, ME) in accordance with the manufacturer’s instructions. Pre- and post-challenge sera from the RP vaccine group (the only vaccine utilized here that does not induce antibodies to the NP) were also tested with this ELISA to characterize the detection of anti-NP antibodies post-challenge.Enzyme-linked lectin assay (ELLA) and neuraminidase inhibition (NI) to detect N1 antibody in serum from challenged chickensThe ELLA assay was performed in accordance with a previously published protocol with minor modifications (4). Absorbance data were fit to a non-linear regression curve with Prism 9.5 (GraphPad Software LLC, Boston, MA) to determine the effective concentration, and the 98% effective concentration (EC98) of the N1 source virus was subsequently used for NI assays.To detect N1 antibody with the optimized N1 NA concentrations, serum samples from the sham, SEP-22-N9, and RP vaccinated groups collected pre-challenge, 7, 10 and 14DPC, were heat inactivated at 56°C for one hour and diluted 1:20 and 1:40 using sample dilution buffer. Equal volumes of the N1 NA source virus at a concentration of 2X EC98 was added to each of the diluted serum samples. Then 100µl of the serum-virus mixture was added to the fetuin coated plates after the fetuin plates were washed as described above for the NA assay. Fetuin plates with the serum-virus mixture were then incubated overnight (approximately 17-19hr) at 37°C. The NA assay protocol described above was followed for the remaining NI assay steps.The percent NI activity of individual serum samples was determined by subtracting percent NA activity from 100. To calculate the percent NA activity, the average background absorbance value was subtracted from the sample absorbance value. The result was then divided by the average value of the NA source virus only (no serum) wells then multiplying by 100. A cut-off value for NI activity for positive detection of N1 antibody from chickens post-challenge was calculated by adding three standard deviations to the mean value obtained from pre-challenge sera of corresponding vaccine group for each dilution tested (1:20 and 1:40).References1. Kapczynski DR, Sylte MJ, Killian ML, Torchetti MK, Chrzastek K, Suarez DL. Protection of commercial turkeys following inactivated or recombinant H5 vaccine application against the 2015U.S. H5N2 clade 2.3.4.4 highly pathogenic avian influenza virus. Vet Immunol Immunopathol. 2017;191:74-9. Epub 2017/09/13. doi: 10.1016/j.vetimm.2017.08.001.2. Das A, Spackman E, Pantin-Jackwood MJ, Suarez DL. Removal of real-time reverse transcription polymerase chain reaction (RT-PCR) inhibitors associated with cloacal swab samples and tissues for improved diagnosis of Avian influenza virus by RT-PCR. Journal of Veterinary Diagnostic Investigation. 2009;21(6):771-8.3. Spackman E, Senne DA, Myers TJ, Bulaga LL, Garber LP, Perdue ML, et al. Development of a real-time reverse transcriptase PCR assay for type A influenza virus and the avian H5 and H7 hemagglutinin subtypes. Journal of Clinical Microbiology. 2002;40(9):3256-60.4. Bernard MC, Waldock J, Commandeur S, Strauss L, Trombetta CM, Marchi S, et al. Validation of a Harmonized Enzyme-Linked-Lectin-Assay (ELLA-NI) Based Neuraminidase Inhibition Assay Standard Operating Procedure (SOP) for Quantification of N1 Influenza Antibodies and the Use of a Calibrator to Improve the Reproducibility of the ELLA-NI With Reverse Genetics Viral and Recombinant Neuraminidase Antigens: A FLUCOP Collaborative Study. Front Immunol. 2022;13:909297. Epub 2022/07/06.

It is urgently needed to update the comprehensive analysis about the efficacy or effectiveness of COVID-19 vaccines especially during the COVID-19 pandemic caused by SARS-CoV-2 Delta and Omicron variants. In general, the current COVID-19 vaccines showed a cumulative efficacy of 66.4%, 79.7%, and 93.6% to prevent SARS-CoV-2 infection, symptomatic COVID-19, and severe COVID-19, respectively, but could not prevent the asymptomatic infection of SARS-CoV-2. Furthermore, the current COVID-19 vaccines could effectively prevent COVID-19 caused by the Delta variant although the incidence of breakthrough infection of the SARS-CoV-2 Delta variant increased when the intervals post full vaccination extended, suggesting the waning effectiveness of COVID-19 vaccines. In addition, one-dose booster immunization showed an effectiveness of 74.5% to prevent COVID-19 caused by the Delta variant. However, current COVID-19 vaccines could not prevent the infection of Omicron sub-lineage BA.1.1.529 and had about 50% effectiveness to prevent COVID-19 caused by Omicron sub-lineage BA.1.1.529. Furthermore, the effectiveness was 87.6% and 90.1% to prevent severe COVID-19 and COVID-19-related death caused by Omicron sub-lineage BA.2, respectively, while one-dose booster immunization could enhance the effectiveness of COVID-19 vaccines to prevent the infection and COVID-19 caused by Omicron sub-lineage BA.1.1.529 and sub-lineage BA.2. Two-dose booster immunization showed an increased effectiveness of 81.8% against severe COVID-19 caused by the Omicron sub-lineage BA.1.1.529 variant compared with one-dose booster immunization. The effectiveness of the booster immunization with RNA-based vaccine BNT162b2 or mRNA-1273 was over 75% against severe COVID-19 more than 17 weeks after booster immunization whereas the heterogenous booster immunization showed better effectiveness than homologous booster immunization. In summary, the current COVID-19 vaccines could effectively protect COVID-19 caused by Delta and Omicron variants but was less effective against Omicron variant infection. One-dose booster immunization could enhance protection capability, and two-dose booster immunization could provide additional protection against severe COVID-19.