U.S. drugmaker Merck & Co. joined Gilead Sciences Inc. on April 27 in lending support to India as the world’s second-most populous country scrambles to address drug shortages and bring a raging new wave of Covid-19 cases under control.

Novartis said on Tuesday that a large British study of the Swiss drugmaker’s cholesterol-lowering medicine Leqvio is not expected to be completed until 2026, a year later than expected, as Covid-19 infections made participant recruitment difficult.

European countries prepared on April 21 to resume deliveries of Johnson & Johnson’s Covid-19 vaccine and speed up the rollout after Europe’s drug regulator backed the shot.

Japanese health authorities are concerned that variants of the coronavirus are driving a nascent fourth wave in the pandemic with just 109 days remaining until the Tokyo Olympics.

One dose of Pfizer COVID-19 vaccine offers an immune response similar to that generated by infection and could also offer protection from variants to people who have previously had the virus, a British study said on March 26.

EU leaders voiced frustration on March 25 over a massive shortfall in contracted deliveries of AstraZeneca Covid-19 vaccines, as a third wave of infections surged across Europe.

Multiple countries across Europe and parts of Asia suspended the use of AstraZeneca’s Covid-19 vaccine over fears the medication is leading to the development of blood clots in some patients who have received the medication.

Confidence in Covid-19 vaccines is growing, with people’s willingness to have the shots increasing as they are rolled out across the world and concerns about possible side effects are fading, a 14-country survey showed on March 5.

AstraZeneca and Oxford University’s Covid-19 vaccine is more effective when its second dose is given three months after the first, instead of six weeks, a peer-reviewed study published in The Lancet medical journal showed on Feb. 19.

The World Health Organization listed AstraZeneca’s Covid-19 vaccine for emergency use, widening access in the developing world, while sources said the EU is in talks with Moderna on buying more vaccines.