Juan Carlos Zevallos is latest government official in South America to resign over coronavirus vaccine scandals.
The United States has authorised Johnson & Johnson’s COVID-19 vaccine for emergency use, adding a third jab to its medical toolbox to fight one of the world’s worst coronavirus outbreaks.
The Food and Drug Administration (FDA) said on Saturday that Johnson & Johnson’s single-dose vaccine offered strong protection against serious illness, hospitalisations and death.
One dose was 85 percent protective against the most severe COVID-19 illness, according to a study that spanned three continents – protection that remained strong even in countries such as South Africa, where one of the coronavirus variants of most concern is spreading.
“The authorisation of this 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 United States,” said the US regulator’s acting director Janet Woodcock.
Shipments of a few million doses to be divided among states could begin as early as Monday.
By the end of March, Johnson & Johnson has said it expects to deliver 20 million doses to the US, and 100 million by mid-year.
US President Joe Biden hailed the authorisation of the third vaccine, but cautioned Americans against celebrating too soon.
“Things are still likely to get worse again as new variants spread,” he said in a statement, urging people to continue washing their hands, wearing masks, and maintaining social distancing.
“There is light at the end of the tunnel, but we cannot let our guard down now or assume that victory is inevitable,” he said.
In large clinical trials, the Johnson & Johnson vaccine’s efficacy against severe disease was 85.9 percent in the US, 81.7 percent in South Africa, and 87.6 percent in Brazil. Overall, among about 44,000 participants across all regions, the efficacy against severe COVID-19 was 85.4 percent, but it fell to 66.1 percent when including moderate forms of the disease.
Crucially, analyses of various demographic groups revealed no marked differences across age, race, or people with underlying conditions.
Dr Francis Collins, director of the National Institutes of Health, called the FDA’s emergency approval for the Johnson & Johnson shot “really good news”.
“The most important thing we can do right now is to get as many shots in as many arms as we can,” he said.
The Johnson & Johnson vaccine is the third to be greenlit in the US after Pfizer/BioNTech’s and Moderna’s were provisionally approved in December.
The company also is seeking authorisation for emergency use of its vaccine in Europe and from the World Health Organization.
More than 65 million people in the US have so far received at least one shot of either the Pfizer or Moderna jabs, both of which require two shots and have an efficacy rate of approximately 95 percent against all forms of COVID-19 from the classic coronavirus strain.
The two vaccines use new messenger RNA technology to create an immune response, and both must be shipped frozen to remain effective.
The one-shot Johnson & Johnson shot involves a more conventional approach. It uses a common cold virus to introduce coronavirus proteins into cells to trigger an immune response – the same technology the company used in making an Ebola vaccine, and similar to the COVID-19 vaccines made by the United Kingdom’s AstraZeneca and China’s CanSino Biologics.
Though slightly less protective than the Pfizer and Moderna vaccine, the Johnson & Johnson shot remains stable for at least three months at normal refrigerator temperatures, making it easier to vaccinate larger numbers of people, even in areas with poor transportation and storage infrastructure.
Dr Janet Woodcock, the FDA’s acting commissioner, told reporters the agency believes “people should take the vaccine they are able to access” as each of the shots will prevent hospitalizations and deaths.
Local health officials in the US are looking to use the Johnson & Johnson option in mobile vaccination clinics, homeless shelters, even with sailors who are spending months on fishing vessels – communities where it is hard to be sure someone will come back in three to four weeks for a second vaccination.
Dr Ali Fattom, immunologist and adjunct professor at the University of Michigan, US, said the approval of a third vaccine was a “relief”.
“It is good news as there are great issues in distribution and obtaining vaccines,” he said, adding that the Johnson & Johnson jab was a good option for developing countries.
“Poorer countries do not have the infrastructure and may not have the capacity to monitor people and call them back for a second shot,” he told Al Jazeera.
“So this is very good news for the developing world, as you will be using already existing infrastructure. You need regular refrigerators, not specialised freezers.”