About vaccines

Background In the United States (US), three vaccines are currently available for primary vaccination and booster doses to prevent coronavirus disease 2019 (COVID-19), including the 2-dose messenger ribonucleic acid (mRNA) BNT162b2 (COMIRNATY®, Pfizer Inc) and mRNA-1273 (SPIKEVAX®, Moderna Inc) vaccines, which are preferred by the Centers for Disease Control and Prevention’s (CDC) Advisory Committee on Immunization Practice (ACIP), and the adenovirus vector Ad26.COV2.S (Johnson & Johnson) vaccine. A substantial body of evidence has now been published on the real-world effectiveness and waning of the primary series and booster doses against specific SARS-CoV2-variants. // 3.4.2022

BACKGROUND: Vaccination has been effective in ameliorating the impact of COVID-19. However, estimation of vaccine effectiveness (VE) is still unavailable for some widely used vaccines and underrepresented groups. Here, we report on the effectiveness of a nation-wide COVID-19 vaccination program in Mexico. // 5.4.2022

COVID-19 vaccination protects against the potentially serious consequences of SARS-CoV2 infection, but some people have been hesitant to receive the vaccine because of reports that it could affect menstrual bleeding. To determine whether this occurs, we prospectively recruited a cohort of 79 individuals, each of whom recorded details of at least three consecutive menstrual cycles, during which time they each received at least one dose of COVID-19 vaccine. We find that either dose of the COVID-19 vaccine is associated with a delay to the subsequent period in spontaneously cycling participants (2.3 days after dose 1; 1.3 days after dose 2) but this change rapidly reverses. No change to timing was detected in those on hormonal contraception. // 30.3.2022

A new study presented the differences among total anti-SARS-CoV-2 antibodies following SARS-CoV-2 Pfizer primary and booster vaccinations. // 24.3.2022

Vaccines are the most important means to overcome the SARS–CoV–2 pandemic. They induce specific antibody and T–cell responses but it remains open how well vaccine-induced immunity is preserved over time following homologous and heterologous immunization regimens. Here, we compared the dynamics of humoral and cellular immune responses up to 5 months after homologous or heterologous vaccination with either ChAdOx1–nCoV–19 (ChAd) or BNT162b2 (BNT) or both. // 27.3.2022

Objectives: The rapid spread of the Omicron variant (B.1.1.529) alongside evidence of a relatively rapid waning of the third dose prompted Israel to administer a fourth dose of the BNT162b2 vaccine on January 2022. // 24.3.2022

A research paper published in the New England Journal of Medicine has demonstrated how a third dose of Pfizer-BioNTech (BNT162b2) vaccine administered in a median period of 10.8 months after the second one bestowed 95.3% efficacy against coronavirus disease 2019 (COVID-19), in comparison with two doses of the same vaccine during a median follow-up of 2.5 months. // 24.3.2022

The BA.1 sub-lineage of the Omicron (B.1.1.529) variant, first detected in the UK in mid-November 2021, rapidly became the dominant strain partly due to reduced vaccine effectiveness. An increase in a second Omicron sub-lineage BA.2 was observed in early January 2022. In this study we use a test-negative case control study design to estimate vaccine effectiveness against symptomatic disease with BA.1 and BA.2 after one or two doses of BNT162b2, ChAdOx1-S or mRNA-1273, and after booster doses of BNT162b2 or mRNA-1273 during a period of co-circulation. Overall, there was no evidence that vaccine effectiveness against symptomatic disease is reduced following infection with the BA.2 sub-lineage as compared to BA.1. // 24.3.2022

Background The rate at which COVID-19 vaccine effectiveness wanes over time is crucial for vaccination policies, but is incompletely understood with conflicting results from different studies. // 23.3.2022

A recent study posted to the bioRxiv* preprint server evaluated the effects of the waning of antibodies after coronavirus disease 2019 (COVID-19) infection or vaccination. // 22.3.2022

A recent study assessed the impact of COVID-19 vaccines on unvaccinated populations and analyzed the various vaccination policies in Israel. // 22.3.2022

This report describes effectiveness of mRNA COVID-19 vaccination in preventing COVID-19 associated invasive mechanical ventilation and death after receiving 2 or 3 vaccine doses. // 18.3.2022

Scientists evaluate the humoral and cellular immune responses in individuals who have received a third booster dose of mRNA-based COVID-19 vaccine. // 17.3.2022

Researchers estimate the impact of COVID-19 booster doses on infection in a vaccinated population of young adults during Omicron-dominant period. // 16.3.2022

Background Omicron variant viruses spread rapidly, even in individuals with high vaccination rates. This study aimed to determine the utility of the antibody against the spike protein level as a predictor of the disease course of COVID 19 in vaccinated patients. // 12.3.2022

Researchers evaluated the immune responses after boosting with Pfizer's BNT162b2 vaccine. // 11.3.2022

Background: While booster vaccinations clearly reduce the risk of severe COVID-19 and death, the impact of boosters on SARS-CoV-2 infection has not been fully characterized: doing so requires understanding their impact on asymptomatic and mildly symptomatic infections that often go unreported but nevertheless play an important role in spreading SARS-CoV-2. // 9.10.2022

In a recent study posted to the medRxiv* pre-print server, researchers evaluated the severity of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Omicron (B.1.1.529) infections between December 23, 2021, and February 20, 2022, in Qatar to understand how Omicron subvariants, vaccination, and prior infection status impacted these cases. // 8.3.2022

The first 6 months of US data after nearly 300 million doses show results consistent with preauthorization trials and early post-authorization surveillance. About 1 in 1000 have an adverse effect. // 7.3.2022

Scientists hypothesize that antibody-specific responses vary during vaccine breakthrough infections in a variant-specific manner. // 7.3.2022

Kennedy Stonum, a high school junior, deflected repeated entreaties from her father to please just get vaccinated against covid-19.// 4.3.2022

Nature Communications - COVID-19 vaccines are effective in preventing disease, but the extent of protection against transmission is unclear. // 4.3.2022

There is increasing evidence that the risk of SARS-CoV-2 infection among vaccinated individuals is variant-specific, suggesting that protective immunity against SARS-CoV-2 may differ by variant. We enrolled vaccinated (n = 39) and unvaccinated (n = 11) individuals with acute, symptomatic SARS-CoV-2 Delta or Omicron infection and performed SARS-CoV-2 viral load quantification, whole-genome sequencing, and variant-specific antibody characterization at the time of acute illness and convalescence. // 3.3.2022

Background SARS–CoV–2 continues to spread despite fast vaccine rollout, which could be attributed to waning immunity or to a reduced protection against some variants. A thorough characterization of vaccine protection and its duration in time is needed to inform vaccination policies and enhance public trust. // 3.3.2022

A new study posted on the medRxiv* preprint server investigated the difference between the likelihood of symptoms, 12 weeks after SARS-CoV-2 infection, among individuals who received two COVID-19 vaccination doses and unvaccinated individuals. // 27.2.2022

@ENirenberg: While MDPI continues to live down to its reputation and prove that it should never have been taken off Beall's list and the usual suspects continue to disinform, let's discuss what this study actually d...… // 26.2.2022 About Alden et. al. 2022 study

New Kaiser Permanente research published February 21, 2022 in Nature Medicine shows that while Moderna COVID-19 vaccine protection is strong against coronavirus infection by the delta variant, it is not as strong against infection from the omicron variant. // 24.2.2022

A new study examined how the quantity and quality of antibody and memory B cell responses to SARS-CoV-2 change temporally and with the number of exposures to antigens. // 24.2.2022

In a recent study posted to the medRxiv* preprint server, researchers estimated the comparative virulence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) between the vaccinated and unvaccinated subjects hospitalized with coronavirus disease 2019 (COVID-19) in Canada. // 23.2.2022

In a recent investigation posted to the journal JAMA Internal Medicine,* researchers estimate the risk of a repeated allergic reaction to the second severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) messenger ribonucleic acid (mRNA) vaccine dose in those with a history of allergic responses following the first dose by conducting a systematic review and meta-analysis. // 22.2.2022