Health experts address questions: Vaccines show promise in fight against COVID-19 spread

"If enough people around you are protected or immune, then those who are not protected are still very unlikely to get it, because there’s not enough to go around, to spread," said Dr. Martin Backer, associate director of the vaccine center at NYU Langone Hospital — Long Island in Mineola.

When someone does contract the virus, that person is much less likely to transmit it to others, he said.

"Any little outbreak that could start, it is extinguished because people are protected, if you have enough people who are vaccinated," Backer said.

"It’s no good to have a vaccine that’s safe and effective but people refuse to get it," Backer said.

He said it’s unclear what percentage of Americans must get vaccinated to achieve herd immunity and greatly reduce the chance of transmission, but, he said, it likely is at least 75%.

"Even though this has been an accelerated process, the science is not being compromised," said Backer, who is helping supervise the Long Island part of the Phase 3 trial for AstraZeneca. Safety is being carefully evaluated, he said.

"I don’t think it would be eradicated, but I think we would push down the number of new infections to very, very low numbers," said Dr. Sharon Nachman, chief of pediatric infectious diseases at Stony Brook Medicine.

Backer said that depends on many factors, but, he said, "it does make sense to hope" that could occur by next fall. Until then, we’ll still need to wear masks, practice social distancing, avoid crowds and take other precautions, he said.

Health care workers will be among the first, Nachman said. Other priority populations would include "the elderly, and those with medical conditions that are high risk for COVID," said Dr. Mark Jarrett, chief quality officer at Northwell Health, based in New Hyde Park.

Months, Nachman said. If you’re not considered the highest priority and want to receive a vaccine, you might consider trying to join a clinical trial for vaccines still being studied, she said.

Yes, Backer said, because all four are targeting the same part of the virus.

"The fact these two show protection makes us feel optimistic and encouraged that the next ones are hopefully going to show good protection as well," he said.

The more vaccines that are effective, the quicker the public can get vaccinated, he said.

"We’re going to need as many safe and effective vaccines as possible to be able to vaccinate a very large proportion of the population which is at risk," he said.

"We don’t know the durability of this protection," Backer said. "How long is this protection going to last?"

It’s not clear whether people who receive the vaccines would be infectious if they contract the virus, Nachman said. Data the companies submit will help answer that question, she said.

National chains such as CVS, Walgreens, Rite Aid and Stop & Shop are part of a federal plan to administer vaccines. Hospitals and independent pharmacies hope to distribute them.

Nidhin Mohan, who owns the independent New Island Pharmacy in Deer Park, said, "This will be taxing on the health care industry, and if we can all provide the vaccine, it's going to reduce the load on the entire industry."

Around Dec. 15, enough doses to administer vaccines to about 170,000 people, Gov. Andrew Cuomo announced Dec. 2. That first batch, from the pharmaceutical company Pfizer, is set to go to residents and personnel of nursing homes, and the next batches, or any left over from the first, would be set aside for certain health care workers, such as those who work in emergency rooms or in intensive care units, he said.

Two weeks later, the biotech company Moderna is to deliver a batch of its vaccine to the state, with Pfizer continuing to ship a second and successive batches.

To be effective, the vaccines require a double dosage, to be taken 21 days after the first.

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