As of February 2022, mRNA-based vaccine Comirnaty, developed by Pfizer/Biontech, was the leading COVID-19 vaccine by efficacy rate, showing around 95 percent of efficacy against COVID-19. This statistic illustrates the comparison of select COVID-19 vaccines worldwide, by efficacy.

As of February 2022, the latest COVID-19 vaccine by Sanofi/GlaxoSmithKline showed a 77 percent efficacy against the Delta variant of the coronavirus. This statistic illustrates the comparison of select COVID-19 vaccines worldwide, by their efficacy against the Delta variant.

As of mid-December 2020, the COVID-19 vaccine from the Biontech/Pfizer cooperation showed significant lower rates of severe adverse events than Moderna's product, with the exception of chills where Moderna showed a lower rate. During November, both sites reported nearly the exact same efficacy of around 95 percent of their vaccines.

BNT162b2 covid-19 vaccine summary of findings table (RCT).

BNT162b2 covid-19 vaccine summary of findings table (observational).

In line with encountering the world with the emergence of vaccine-resistance variants of SARS-CoV-2, 15,669,529 samples that received COVID-19 vaccines until April 2023 were investigated as two doses in the first phase and booster vaccinations in the second phase. The analysis shows that D614G and P681 mutations occurred in both phases. The E484 and Y655 mutations significantly emerged during the second phase. The 762-889 and 254-381 regions are revealed as conserved parts and could be considered in vaccine design. The Kruskal–Wallis test revealed a significant reduction in single mutations between populations with 20%–50% and those with 70%–100% vaccination coverage (p=0.017). The Mann–Whitney U test proposes a link between vaccination and suppression of viral mutation rates. Dynamic modeling suggests that key mutations have facilitated the virus’ evolution and immune escape. The study’s findings are crucial for understanding virus genome mutations, especially E614 and P681 in Delta and E484 and H655 in Omicron. This highlights the need to adjust strategies and strengthen global efforts in combating the pandemic.

By the end of January 2022, almost five billion COVID-19 vaccine doses were manufactured in China, making the country by far the largest producer of COVID-19 vaccines globally. While most vaccines were for domestic use, a considerable portion of vaccines was exported via sales and donations, mainly to lower or middle-income countries. In comparison to western mRNA vaccines such as Comirnaty or Spikevax, inactivated COVID-19 vaccines developed by Sinovac and Sinopharm have a lower efficacy rate.

IntroductionThe coronavirus disease 2019 (COVID-19) pandemic has resulted in devastating health and economic consequences worldwide. Vaccination has been a central pillar for COVID-19 prevention and control. Understanding the immunomodulatory effects of helminth infections on COVID-19 vaccine-induced immune responses and vaccine efficacy is crucial to the development and deployment of effective vaccination strategies in low- and middle-income countries with a high prevalence of worms.MethodsIn September 2022, we conducted a cross-sectional, population-based survey in five Schistosoma mansoni endemic villages in Mayuge District, Uganda (n = 450). The prevalence of schistosomiasis and soil-transmitted helminths was determined by the Kato-Katz (KK) technique on two stool samples collected from each participant. A subset of individuals (n = 204) were interviewed in a COVID-19 vaccination survey. IgG levels against the SARS-CoV-2 spike S1 subunit (anti-S1 IgG) were measured by enzyme-linked immunosorbent assay (ELISA) in collected serum samples.ResultsThe overall schistosomiasis and hookworm prevalence rates in the five villages were 36.4% (166/450) and 36.9% (168/450), respectively. Within the cohort, 69.78% (314/450) of the subjects had a positive anti-S1 IgG response. COVID-19 vaccination coverage among the interviewed participants was 93.14% (190/204; 95% CI, 88.8% − 95.9%). However, 81% (154/190) of COVID-19 vaccinees had an anti-S1 IgG titre ≤200. In an adolescent group receiving a single dose of the BNT162b2 mRNA vaccine (n = 23), an inverse correlation was observed between anti-S1 IgG antibody level/titre and faecal egg count. Within the above group, anti-S1 IgG levels/titres were significantly lower in subjects with moderate or heavy S. mansoni infection (n = 5) than those in KK-negative individuals (n = 9).ConclusionAlthough the acceptance rate of COVID-19 vaccination was high, the majority of participants received only a single vaccine dose and the overall anti-S1 IgG titres in confirmed vaccinees were low. Moderate-to-heavy schistosome infections blunted the antibody responses following vaccination with a single dose of BNT162b2. These observations confirm the necessity for a second COVID-19 vaccine dose for two-dose primary immunization series and call for implementation research that may inform the development of a ‘treat and vaccinate’ policy during vaccination roll-out in regions with heavy worm burdens.

Additional file 3: Table S3. Vaccine booster effectiveness against viral variants. Studies of vaccine booster effectiveness against viral variants. Related to Table 2.

IntroductionDespite the efficacy and safety of SARS-CoV-2 vaccines, inflammatory and/or thrombotic episodes have been reported. Since the impact of COVID-19 vaccines on the endothelium remains uncertain, our objective was to assess endothelial activation status before and 90 days after the third dose of the BNT162b2 mRNA COVID-19 vaccine.MethodsA prospective longitudinal study was conducted at University General Hospital of Albacete, involving 38 healthy health-care workers. Serum levels of endothelial markers (endocan and sVCAM-1) and spike S1-specific IgG antibodies were determined before and at 7, 15, 24 and 90days following vaccination. To analyze each participant´s individual response, we calculated relative increases/decreases (delta values) in endothelial markers and antibodies concentrations compared to their pre-vaccination levels.ResultsWe identified two significantly distinct profiles of endothelial markers response, characterized by either increased or decreased serum levels of endocan and sVCAM. Incremental and decremental response groups did not differ in terms of age, sex, cardiovascular risk factors, previous SARS-CoV-2 infection and influenza vaccine co-administration. However, these responses were significantly associated with the relative spike-specific antibody production. Specifically, the greatest relative increase in antibodies was found in the decremental responders. Additionally, the higher delta antibody production was observed in non-previously infected individualsConclusionAdministration of the BNT162b2 booster vaccine triggered a non-homogenous response of endothelial function markers among the study participants. Our findings improve the understanding of individual responses to the mRNA COVID-19 booster vaccine, which could be useful in assessing the need for booster doses, particularly in population at risk of vascular complications.

Potential factors associated with COVID-19 vaccine acceptance and hesitancy.

Table showing the incidence rate of COVID-19 infections and hazard ratios (with 95% confidence intervals) in a cohort of 2762 health care personnel in a tertiary care centre, Mumbai, India.

IntroductionThe government's role in influencing policies related to Coronavirus disease 2019 (COVID-19) vaccine distribution and handwashing practices is essential in controlling the spread of severe acute respiratory syndrome coronavirus 2.MethodsThis study aimed to systematically review published studies to explore the influence of government policies on handwashing and vaccine uptake in Kenya, Uganda and Tanzania to prevent and control COVID-19. A comprehensive search strategy was applied across three databases, and eligibility was determined using strict inclusion and exclusion criteria. We reviewed 9 of 136 research papers following the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) guidelines.ResultsThe findings revealed that the government has a role in influencing policies related to COVID-19 vaccine distribution and handwashing uptake. Employment of public health campaigns and communication strategies by the government in Uganda increased vaccine acceptance and hand hygiene uptake. Similarly, government efforts to make hand hygiene accessible increased the uptake of handwashing in Tanzania. In Kenya, government efforts to increase access to soap and clean water in informal settlements and markets resulted in increased adherence to handwashing practices. Further, government incentives such as cash increased vaccination rates while vaccination reminders combined with cash incentives increased childhood immunization coverage.DiscussionOverall, this review indicates that monitoring and enforcing compliance increases vaccine and handwashing uptake across the three countries. The effectiveness of government policies on handwashing and vaccine uptake is influenced by factors such as safety, efficacy and access to information, among others. Therefore, there is a need to address these factors for the successful implementation of these policies.Systematic review RegistrationPROSPERO ID CRD42023396319, https://www.crd.york.ac.uk/prospero/.