Johnson & Johnson one dose vaccine

Johnson & Johnson's single-dose vaccine protects COVID-19. This sets the stage for a final decision on a new, easier-to-use injection to control the pandemic. Scientists from the Food and Drug Administration (FDA) confirmed that overall, the vaccine is about 66% effective in preventing moderate to severe COVID-19. The agency also said the J&J injection could help speed vaccinations by requiring only one dose instead of two - it is safe to use.

J&J has tested its single-dose option on more than 44,000 people in the United States, Latin America, and South Africa. Since different mutated versions of the virus circulate in different countries, the researchers analyzed the results geographically. J&J had previously announced that the vaccine worked better in the United States, with 72% efficacy against moderate to severe COVID-19, compared to 66% in Latin America and 57% in South Africa. In all countries, it was very effective against the most severe symptoms, and the first results of the study showed no hospitalizations or deaths after 28 days after vaccination.

Although overall efficacy figures may suggest that the J&J candidate is not as potent as its two-dose competitors, all of the world's COVID-19 vaccines have been tested differently, making comparisons nearly impossible. While it would not be surprising if one dose turns out to be slightly weaker than two, policymakers will decide whether it is an acceptable trade-off to get more people vaccinated more quickly. J&J was on its way to becoming the world's first single-dose choice until earlier this month, Mexico announced it would use a one-dose version from Chinese company CanSino. In case the vaccines eventually need to be updated, manufacturers are working on adjustments to their prescriptions.

Moderna announced Wednesday that it is ready to begin testing experimental doses better suited to the South African version of the virus. In all countries, analysis of the J&J vaccine showed that protection began to emerge about 14 days after vaccination. But at 28 days after vaccination, there were no hospitalizations or deaths in the vaccinated group compared to 16 hospitalizations and seven deaths in study recipients who received a sham injection. The FDA said the effectiveness and safety were consistent across all racial groups, including black and Latino participants.

All the COVID-19 vaccines in the world have been tested differently, making comparisons nearly impossible. It wouldn't be surprising if one dose turns out to be a little weaker than two doses, and lawmakers will decide if that's an acceptable trade-off for more people to get vaccinated faster. J&J has another large study underway to see if the second dose of its vaccine works better, increasing the chance that countries will eventually add a booster if warranted. Like other COVID-19 vaccines, the main side effects of the J&J injection are injection site pain and flu-like fever, fatigue, and headache.

No study participant experienced a severe allergic reaction, called anaphylaxis, which is a rare risk from some other COVID-19 injections, although one experienced a less severe reaction.