With inputs from Dr Monica Vasudev

BCG vaccine enhances immune protect against SARS-CoV-2 

A preprint study in hamsters has shown that the BCG vaccine reduced the SARS-CoV-2 viral load in the lungs as well as bronchopneumonia. The vaccine led to an increase in alveolar macrophages in the lungs, reduced interstitial macrophage leading to decreased IFN-associated gene expression and recruitment of higher levels of Th1, Th17, Treg, CTLs, and Tmem cells. The authors concluded that combining the BCG vaccine with the currently available COVID-19 vaccines “may offer synergistic protection” though studies are needed to confirm this… (Source: bioRxiv, March 15, 2022)

Pfizer and Moderna seek approval for second booster doses

Pfizer-BioNTech have applied for authorization for second booster shot, but only for persons older than 65 years who have been vaccinated. Moderna has also sought emergency authorization for a booster shot of its Covid-19 vaccine for all adults ≥ 18 years who have completed their primary vaccination. However, the age groups would be at the discretion of the CDC… (Source: Medscape, March 18, 2022).

Long-term adverse mental health symptoms in patients with severe COVID-19

Analysis of data from Denmark, Estonia, Iceland, Norway, Sweden and the UK between March 27, 2020, and August 13, 2021 shows that 22% patients with COVID-19 who had been confined to bed on account of their illness for ≥7 days, which was 16 months in this multicohort study, were at a greater risk of suffering long-term depression with a prevalence ratio of 1.61) and anxiety (PR 1.43) versus those who had COVID-19 but were not bedridden (PR 0.83 and PR 0.77, respectively)… (Source: The Lancet Public Health, March 14, 2022)

Low efficacy of fourth booster dose against Omicron 

A NEJM study involving healthy young healthcare workers in Israel, which analysed the effectiveness of fourth dose of mRNA Covid-19 vaccine (Pfizer-BioNTech or Moderna) found them to be only marginally effective against Omicron even though both vaccines induced IgG antibodies and increased the titers of neutralizing antibodies. The fourth dose can restore the antibody levels generated after the third vaccine dose. However, people at high risk of severe disease could benefit from the fourth dose, according to the authors”… (Source: New England Journal of Medicine, March 16, 2022)