Washington (USA) | Jagran News Desk: The United States of America (USA) on Saturday approved Johnson and Johnson's single-dose COVID-19 vaccine -- Janssen -- for emergency use authorisation. Johnson and Johnson is the third authorised COVID-19 vaccine in the US.

The US Food and Drug Administration has said that the Janssen COVID-19 vaccine is "safe and effective" in preventing the infection. It also said that the available data shows that the vaccine's known and potential benefits outweigh its known and potential risks, supporting the company's request for the vaccine's use in people of 18 years of age and older.

"The authorisation of this (Johnson and Johnson) vaccine expands the availability of vaccines, the best medical prevention method for COVID-19, to help us in the fight against this pandemic, which has claimed over half a million lives in the US," the FDA said in a statement, as reported by Reuters.

Why Johnson and Johnson COVID-19 vaccine is special?

The Johnson and Johnson COVID-19 vaccine is a single-dose vaccine that does not require special storage. On the other, Pfizer Moderna vaccines, which are based on new messenger RNA technology, are two-dose vaccines and require special storage.

What about the efficacy rate of the Johnson and Johnson COVID-19 vaccine?

In over 44,000 global trails, the Johnson and Johnson COVID-19 vaccine has found to be 100 per cent effective in preventing hospitalisation and death. In moderate-to-severe cases, the vaccine was 66 per cent effective.

However, the success rate goes higher in the US where the vaccine was found to "72 per cent effective at preventing all COVID-19 and 86 per cent effective at preventing severe cases of the disease", the FDA analysis showed.

In South Africa, where a more contagious variant of the virus has been found, the Johnson and Johnson COVID-19 vaccine has shown an overall efficacy rate of 64 per cent and 82 per cent at preventing severe disease.

How does Johnson and Johnson COVID-19 vaccine compare with others?

The Johnson and Johnson vaccine is an adenovirus vector vaccine while Moderna and Pfizer vaccines are based on new messenger RNA technology. While Janssen is a single-shot vaccine, Moderna and Pfizer vaccines require two doses to show effectiveness against the pathogen.

Moderna and Pfizer vaccines have shown an efficacy rate of 95 per cent but require special transportation facilities. However, medical experts believe that a direct comparison of the Johnson and Johnson vaccine with Moderna and Pfizer vaccines is difficult because the trials were conducted with "different goals".

"It potentially could play a very substantial role if we have enough doses because it’s only a single-dose vaccine and that will make it attractive to people who are difficult to reach," Reuters quoted Dr William Schaffner, an infectious disease expert at Vanderbilt University Medical Center in Nashville, as saying.

Posted By: Aalok Sensharma