Protection of BNT162b2 Vaccine Booster against Covid-19 in Israel

Background: On July 30, 2021, the administration of a third (booster) dose of the BNT162b2 messenger RNA vaccine (Pfizer-BioNTech) was approved in Israel for persons who were 60 years of age or older and who had received a second dose of vaccine at least 5 months earlier. Data are needed regarding the effect of the booster dose on the rate of confirmed coronavirus 2019 disease (Covid-19) and the rate of severe illness. Conclusions: In this study involving participants who were 60 years of age or older and had received two doses of the BNT162b2 vaccine at least 5 months earlier, we found that the rates of confirmed Covid-19 and severe illness were substantially lower among those who received a booster (third) dose of the BNT162b2 vaccine.

Surveillance for Adverse Events After COVID-19 mRNA Vaccination

Question Are mRNA COVID-19 vaccines associated with increased risk for serious health outcomes during days 1 to 21 after vaccination? Findings In this interim analysis of surveillance data from 6.2 million persons who received 11.8 million doses of an mRNA vaccine, event rates for 23 serious health outcomes were not significantly higher for individuals 1 to 21 days after vaccination compared with similar individuals at 22 to 42 days after vaccination.

Variants of SARS-CoV-2

When a virus develops a new mutation, it is called a variant of the original virus. As viruses spread, they constantly change through mutations to their genetic code. Most mutations in the SARS-CoV-2 genome do not affect the functioning of the virus. However, mutations in the spike protein of SARS-CoV-2, which binds to receptors on cells lining the inside of the human nose, may make the virus easier to spread or affect how well vaccines protect people. Other mutations may lead to SARS-CoV-2 being less responsive to treatments for COVID-19.

Randomized Trial of a Third Dose of mRNA-1273 Vaccine in Transplant Recipients

In organ-transplant recipients, the standard two-dose vaccination strategy for coronavirus disease 2019 (Covid-19) has suboptimal immunogenicity.1 Both patients and health care providers have questioned whether a third-dose booster in transplant recipients would be safe and enhance immune response.2 We performed a double-blind, randomized, controlled trial of a third dose of mRNA-1273 vaccine (Moderna) as compared with placebo (the protocol is available with the full text of this letter at NEJM.org; ClinicalTrials.gov number, NCT04885907. opens in new tab).

Long-term Symptoms After SARS-CoV-2 Infection in Children and Adolescents

Children can experience SARS-CoV-2 postviral syndromes, but it is unclear to what extent these individuals are affected by long COVID. Evidence is predominantly limited to select populations without control groups,1-4 which does not allow estimating the overall prevalence and burden in a general pediatric population. We compared symptoms compatible with long COVID in children and adolescents (hereafter “children”) reported within 6 months after SARS-CoV-2 serologic testing.