(Adds Turkey, United Kingdom, United States)
(Reuters) – A growing number of countries are looking at switching to different COVID-19 vaccines for second doses or booster shots after supply delays and safety concerns slowed their vaccination campaigns.
The World Health Organization said on July 12 that the practice was a dangerous trend since there was little data about the health impact. Europe’s drug regulator on July 14 made no definitive recommendations on switching vaccines.
The following countries are considering, or have decided to adopt, such an approach:
CAMBODIA
Cambodian Prime Minister Hun Sen said on Aug. 1 that a booster shot of AstraZeneca’s vaccine would be offered to people who had received two doses of shots from either Sinopharm or Sinovac, while a Sinovac booster should be given to Cambodians fully inoculated with the AstraZeneca shot.
DENMARK
Denmark’s State Serum Institute, which deals with infectious diseases, said on Aug. 2 that combining AstraZeneca’s vaccine with a second shot from either Pfizer-BioNTech or Moderna provides “good protection”.
GERMANY
Germany will offer booster shots of the Pfizer-BioNTech and Moderna vaccines from September to vulnerable individuals such as pensioners and people with weak immune systems, regardless of which vaccine they had previously received.
INDONESIA
Indonesia is considering offering a booster shot to healthcare workers immunized with Sinovac’s vaccine as thousands of them are testing positive for COVID-19.
RUSSIA
Russia’s Direct Investment Fund (RDIF) said on July 30 that trials mixing a first dose of the Sputnik V vaccine with AstraZeneca’s shot revealed no serious side effects and no subsequent coronavirus cases among volunteers.
RDIF said full results from the trial, which was approved on July 26 after being suspended in May by the health ministry’s ethical committee due to a lack of data, would be published this month.
TURKEY
Turkey is allowing people who have been inoculated with Sinovac’s vaccine to receive an additional Pfizer dose as it looks to ease travel to countries that have not approved the Chinese shot, Turkey’s health ministry said on Aug. 16.
UNITED KINGDOM
Britain’s Vaccine Manufacturing & Innovation Centre will seek to combine flu and COVID-19 vaccines into a single shot to speed up booster programmes, The Telegraph reported on Aug. 15.
UNITED STATES
U.S. regulators authorised a third dose from either Pfizer-BioNTech or Moderna on Aug. 13 for people with compromised immune systems who are likely to have weaker protection from two-dose regimens. If a recipient’s original shot is not available, they can be vaccinated with the other one.
(Reporting by Federico Maccioni; Editing by David Clarke)