Although there have been discussions about using different Covid-19 vaccines in combination, World Health Organization (WHO) chief scientist Soumya Swaminathan warned against it, calling it a “dangerous trend.”

The World Health Organization (WHO) forecasts that people most vulnerable to Covid-19, such as the elderly, will need to get an annual vaccine booster to be protected against variants, an internal document seen by Reuters shows.

Medicago and GlaxoSmithKline reported positive interim Phase 2 clinical trial safety and immunogenicity data for Medicago’s plant-derived Covid-19 vaccine candidate, which has been tested in combination with GSK’s pandemic adjuvant.

The first study to directly compare immune reactions between Pfizer’s and AstraZeneca’s Covid-19 vaccines found strong and broadly similar antibody responses in over-80-year-olds after a first dose of either shot, scientists said on April 14.

Covid-19 was the primary or contributing cause of 377,883 deaths in the United States during 2021, with a particularly high toll among the elderly, according to a government report released on March 31.

The majority of people who have had Covid-19 are protected from getting it again for at least six months, a study published on March 17 showed, but older people are more prone to reinfection than younger people.

GlaxoSmithKline will extend a trial testing an experimental rheumatoid arthritis drug on patients suffering from pneumonia related to Covid-19 to focus on the elderly as the company seeks to firm up encouraging findings.

Oxford University and AstraZeneca’s Covid-19 vaccine showed in a study it had 76% efficacy against symptomatic infection for three months after a single dose, which increased if the second shot is delayed, backing Britain’s vaccine rollout policy.

AstraZeneca denied the company’s Covid-19 vaccine is not very effective for people over 65 years old, after German media reports said officials fear the vaccine may not be approved in the European Union for use in the elderly.

Moderna Inc.’s coronavirus vaccine mRNA-1273 became the second to receive emergency use authorization (EUA) from the U.S. Food and Drug Administration, welcome news to a nation with a staggering Covid-19 death toll of more than 307,000 lives lost.