28 June 2021

Nature publishes data on immune responses to SARS-CoV-2 from 180 healthcare workers who received both doses of the Pfizer/BioNTech vaccine. They found that the vaccine induced strong immune responses in everyone who received it; that it was effective against the Alpha variant, but less so against the Beta variant (although 92 percent of people who were vaccinated showed immune responses against it). Source

• The University of Oxford issues a press release with results from the 4-week dosing arm of the Com-COV study, which mixed the Oxford/AstraZeneca coronavirus vaccine with the Pfizer/BioNTech vaccine. Mixing vaccines generated robust immune responses, especially when the Oxford/AstraZeneca vaccine was given first. The researchers noted that mixing doses generated higher antibody levels and T cell responses than two doses of the Oxford/AstraZeneca vaccine, while two doses of the Pfizer/BioNTech generated the highest antibody response, and highest T cell responses were generated by giving a dose of Oxford-AstraZeneca followed by a dose of the Pfizer-BioNTech vaccine. Results from the trial’s 12-week dosing interval group are due soon. Source

• Three weeks before the Olympics begin, coronavirus cases in Tokyo are creeping upwards Japan’s Prime Minister Yoshihide Suga said “We must be on a high state of alert in dealing with the virus.” He added that he would be nimble in adjusting policies to deal with the situation. Source

• In Australia, where only six percent of the population has been fully vaccinated, Sydney and Darwin go into lockdown, while Perth and Canberra impose mask mandates for the first time. Source

• Abu Dhabi starts using facial scanners in airports and malls to detect people with COVID-19. The scanners measure electromagnetic waves, which change if viral RNA is present in a person’s body, and can accurately identify 93.5 percent of infected people. Source

Nature publishes an article demonstrating that mRNA-based coronavirus vaccines induce persistent immune responses that may last for years, although boosters may be needed for people with weakened immune systems, the elderly and those on immunosuppressants. Source

• Oxford University issues a press release with findings that delaying the second dose of the Oxford/AstraZeneca coronavirus vaccine for up to 45 weeks enhanced immune responses – and may be beneficial. Administering a third dose of the vaccine at least six months after the second dose increased antibodies to a level above what was seen a month after their second dose, suggesting that if the vaccine’s effectiveness  wanes it could be boosted with a third dose. Source

• Italy, Spain and France are no longer requiring people to wear masks outside. Source

• As Bangladesh reaches 900,000 cases of COVID-19, it is returning to a national lockdown which has sent tens of thousands of migrant laborers from Dhaka, the capital, to their home villages. Source

• In the US, some infectious disease specialists are recommending that people who got the J & J single-dose coronavirus vaccine may need a booster dose to protect against the Delta variant, although the CDC has not recommended it. “There’s no doubt that the people who receive the J&J vaccine are less protected against disease,” says Dr Michael Lin, who is an Associate Professor of Neurobiology and Bioengineering at Stanford University, “From the principle of taking easy steps to prevent really bad outcomes, this is really a no brainer.” Jason Gallagher, an infectious disease specialist at Temple University said, “… the Delta variant that’s spreading … and really quickly taking over in the U.S. looks a little more concerning in terms of the breakthrough infections with the single-dose vaccines.” Source

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