Dr. Ashish Jha told CNBC’s “The News with Shepard Smith” on Tuesday that US states could make decisions about opening up businesses and economies earlier than predicted if enough people are vaccinated.

“My relatively optimistic view is that we don’t have to wait until the end of summer or even the beginning of summer. If enough people have been vaccinated in late spring, you will really see case numbers come down a lot,” said Jha, dean of the School of Public Health at Brown University. “That will allow us to open up the economy a lot more so that we don’t have to wait and just make sure the infections – the high infection rates we have right now – get better . “

President Joe Biden set a benchmark in the fight against the coronavirus pandemic. He promised to get enough vaccine doses to the states for almost every American by the end of summer. Biden said he would give the government another 200 million doses of the vaccine – half from Pfizer and the other half from Moderna. The deal would increase the country’s vaccine supply to 600 million shots.

“This is enough vaccine to fully vaccinate 300 [million] Americans by the end of summer, the beginning of autumn, “Biden said at the White House on Tuesday.

To vaccinate 300 million people by September 22, the last day of summer, the nation will need 600 million doses at the rate of about 2.4 million shots a day. That assumes it goes beyond the 23 million that have already been bumped. Biden said the government would be sending 10 million shots a week for the next three weeks. That is an increase of almost 20% over what is currently being delivered.

Johnson & Johnson expects results for its Covid vaccine early next week. CNBC’s Meg Tirrell said the company conducted its test on three continents, including South Africa and Brazil, where the highly communicable new variants were identified. This means that Johnson & Johnson’s results could provide vital information on how vaccines developed around the original strain of Covid work against the emerging ones.

Dr. Bruce Becker, associate professor of behavioral medicine and social sciences at Brown University’s School of Public Health, told The News with Shepard Smith that the Johnson & Johnson vaccine requires only one shot and therefore achieves immunity in 14 to 21 years will days.

“The J&J vaccine can vaccinate twice the number of patients for any given vaccine supply – twice the coverage and immunity in less than half the time,” Becker said. “That is a much greater efficiency in blocking the spread of Covid.”

Jha told host Shepard Smith that a single dose would “greatly” aid in vaccination effort, but questioned the company’s manufacturing capacity.

“I think one of the less clear questions is how much stock of J&J vaccines we have.” asked Jha. “There have been some reports that it didn’t go that well, production didn’t go that well, but either way, a dose is so much easier to give as a vaccine.”

The Centers for Disease Control and Prevention published a study Tuesday that found that Covids spread in schools is very low with the right precautions. Jha stated that the US can open schools across the country, but “we have to do it” with preventive measures that include masks and effective ventilation.

Becker underlined the importance of preventive measures and even said that non-compliant students should be excluded from school.

“Masking work, social distancing work, and the deadly misinformation circulated by the previous government and their voices created our current dilemma,” Becker said. “Schools can be opened if the rules are followed exactly.”

Biden said Tuesday “it will be months before we can vaccinate the majority of Americans” and that “masks not vaccines” are the best defense against Covid as Americans wait for their vaccine.