Randomized controlled trials (RCTs) have shown high efficacy of multiple vaccines against SARS-CoV-2 disease (COVID-19), and recent studies have shown the vaccines are also effective against infection. Evidence for the effect of each of these vaccines on ability to transmit the virus is also beginning to emerge. We describe an approach to estimate these vaccines' effects on viral positivity, a prevalence measure which under the reasonable assumption that vaccinated individuals who become infected are no more infectious than unvaccinated individuals forms a lower bound on efficacy against transmission. Specifically, we recommend separate analysis of positive tests triggered by symptoms (usually the primary RCT outcome) and cross-sectional prevalence of positive tests obtained regardless of symptoms. The odds ratio of carriage for vaccine vs. placebo provides an unbiased estimate of vaccine effectiveness against viral positivity, under certain assumptions, and we show through simulations that likely departures from these assumptions will only modestly bias this estimate. Applying this approach to published data from the RCT of the Moderna vaccine, we estimate that one dose of vaccine reduces the potential for transmission by at least 61%, possibly considerably more. We describe how these approaches can be translated into observational studies of vaccine effectiveness.

The inclusion of infants in the SARS-CoV-2 vaccine roll-out is important to prevent severe complications of pediatric SARS-CoV-2 infections and to limit transmission and could possibly be implemented via the global pediatric vaccine schedule. However, age-dependent differences in immune function require careful evaluation of novel vaccines in the pediatric population. Toward this goal, we assessed the safety and immunogenicity of two SARS-CoV-2 vaccines. Two groups of 8 infant rhesus macaques (RMs) were immunized intramuscularly at weeks 0 and 4 with stabilized prefusion SARS-CoV-2 S-2P spike (S) protein encoded by mRNA encapsulated in lipid nanoparticles (mRNA-LNP) or the purified S protein mixed with 3M-052, a synthetic TLR7/8 agonist in a squalene emulsion (Protein+3M-052-SE). Neither vaccine induced adverse effects. Both vaccines elicited high magnitude IgG binding to RBD, N terminus domain, S1, and S2, ACE2 blocking activity, and high neutralizing antibody titers, all peaking at week 6. S-specific memory B cells were detected by week 4 and S-specific T cell responses were dominated by the production of IL-17, IFN-γ, or TNF-α. Antibody and cellular responses were stable through week 22. The immune responses for the mRNA-LNP vaccine were of a similar magnitude to those elicited by the Moderna mRNA-1273 vaccine in adults. The S-2P mRNA-LNP and Protein-3M-052-SE vaccines were well-tolerated and highly immunogenic in infant RMs, providing proof-of concept for a pediatric SARS-CoV-2 vaccine with the potential for durable immunity that might decrease the transmission of SARS-CoV-2 and mitigate the ongoing health and socioeconomic impacts of COVID-19.

As the COVID-19 pandemic continues, the authorization of vaccines for emergency use has been crucial in slowing down the rate of infection and transmission of the SARS-CoV-2 virus that causes COVID-19. In order to investigate the longitudinal serological responses to SARS-CoV-2 natural infection and vaccination, a large-scale, multi-year serosurveillance program entitled SPARTA (SARS SeroPrevalence and Respiratory Tract Assessment) was initiated at 4 locations in the U.S. The serological assay presented here measuring IgG binding to the SARS-CoV-2 receptor binding domain (RBD) detected antibodies elicited by SARS-CoV-2 infection or vaccination with a 95.5% sensitivity and a 95.9% specificity. We used this assay to screen more than 3100 participants and selected 20 previously infected pre-immune and 32 immunologically naïve participants to analyze their antibody binding to RBD and viral neutralization (VN) responses following vaccination with two doses of either the Pfizer-BioNTech BNT162b2 or the Moderna mRNA-1273 vaccine. Vaccination not only elicited a more robust immune reaction than natural infection, but the level of neutralizing and anti-RBD antibody binding after vaccination is also significantly higher in pre-immune participants compared to immunologically naïve participants (p

Abstract Within recent past, coronavirus has shaken the whole world. The world faced a new pandemic of novel coronavirus 2019 (SARS-CoV-2/ COVID-19).It has socioeconomically impacted world population a lot in terms of education, economy as well as physical and mental health. This novel coronavirus is notorious enough that put human health at a great risk. Currently, researchers all over the world aretrying hard to develop a new drug/vaccine for its treatment. In past decades, the world population has faced various viral infectious illness outbreaks. Influenza A, Ebola, Zika, SARS and MERS viruses had whacked public health and economy. Medical science technology achieved the landmark in developing coronavirus (SARS-CoV-2) vaccines that are approved currently for emergency use. Some of the recently approved vaccines are developed by Pfizer and Moderna, Johnson and Johnson, Gam-COVID-vac (Sputnik V), Bharat Biotech (covaxin) andOxford-AstraZeneca vaccines (covishield) (Badenet al., 2021). Here, a short review is drafted focusingon infection, immune system, pathogenesis, phylogenesis, mode of transmission and impact of coronavirus on health and economy and recent developments in treating COVID-19.

Doses distributed and people initiating vaccination (1st dose received) are for both Moderna and Pfizer BioNTech COVID-19 vaccine and reflect current data available as of 9:00am ET on the day of reporting. Data will be regularly updated on Monday, Wednesday and Friday. Updates will occur the following day when reporting coincides with a federal holiday. Healthcare providers report doses to federal, state, territorial, and local agencies up to 72 hours after administration. There may be additional lag for data to be transmitted from the federal, state, territorial, or local agency to CDC. A large difference between the number of doses distributed and the number of people initiating vaccination is expected at this point in the COVID vaccination program due to several factors, including delays in reporting of administered doses and management of available vaccine stocks by jurisdictions and federal pharmacy partners. Numbers reported on CDC’s website are validated through a submission process with each jurisdiction and may differ from numbers posted on other websites. Differences between reporting jurisdictions and CDC’s website may occur due to the timing of reporting and website updates. The process used for reporting doses distributed or people vaccinated displayed by other websites may differ. When the “Rate per 100,000” metric is selected for both doses distributed and people initiating vaccination (1st dose received), federal entities will display as N/A because population-based rates are not applicable. Doses distributed and administered for federal entities will display as counts when the “Counts” metric is selected.