Good News On Vaccine Front, But Much Work Needs To Be Done: Dr. Purvi Parikh

Dr. Purvi Parikh, right, on CNBC July 9, 2020, being interviewed by host Meg Tirrell, on how vaccine trials work, who can participate and how long until we know which drugs will be effective. (Photo: videograb from

In a recent interview on CNBC, New York University Langone Health Allergist & Immunologist Dr. Purvi Parikh, said there have been some positive results from the Pfizer vaccine trials that she is involved with, but cautioned that it would take 12 to 18 months to reach definitive conclusions about the effectiveness of the various ongoing vaccine trials around the world, and that the public still must follow simple protocols  in their lives such as wearing a mask, frequent hand-washing and social distancing, which could help save many lives.

Dr. Parikh was speaking July 9, 2020, on the program Healthy Returns: The Path Forward, a weekly live-stream from CNBC. The discussion with Dr. Parikh focused on “Understanding Vaccine Studies” a half hour interview by Meg Tirrell on how vaccine trials work, who can participate, and how long until we know which drugs will be effective.

Parikh is running clinical trials for potential Covid 19 vaccines from Pfizer and Astrazeneca which just partnered with Oxford University’s ongoing vaccine trials.

“We have some optimistic and promising news that came out just last week,” from the Pfizer one-two study, Dr. Parikh said. Despite the initial study involving just 45 patients and not being peer-reviewed, yet, it looks like the vaccines are showing that not only are antibodies being able to be formed at very high levels, but they are also functional, meaning that they are able to neutralize the virus. “So this is what we are looking for to get ahead of the pandemic.”

Dr. Parikh noted that the technology in this study is different in that it is not an inactivated vaccine, and it does not have dead particles from other parts of the actual coronavirus vaccine. “Basically it tricks your own immune system to develop immunity,” tricking the cells into thinking a person has been infected. “So we’re hoping it’s a safe and effective way to mass protection against the coronavirus.” Currently, two doses are being looked at to progressively strengthen a person’s immunity.

Discussing different aspects of vaccine trials, Dr. Parikh described the four phases involved in clinical trials, the first phase starting with a smaller sample, focuses on the safety aspect to detect any serious side-effects and tolerance of the vaccine. The second phase expands the number of candidates and focuses on the size of the dosage and what was the smallest dose that could produce an immune response. That would ensure fewer side-effects and more vaccine available for what is a global  pandemic because shortages are anticipated, Dr. Parikh said.

Phase three expands to a whole general population once the safe and effective dose has been determined. This stage could include 30,000 or so candidates. “And that phase is we want to test gthe really high resk people, healthcare workers, certain ethnicities that may be more pre-disposed to COVID-19 versus others, the elderly. That will really show us and give us good, what we call, statistical significance.”

In the fourth phase, which comes after the vaccine is approved, the candidates continue to be monitored for safety and efficacy of the vaccine for at least two more years, she noted.

Signing up for the trials can be done on the National Institutes of Health website by tracking COVID-19 vaccine trials or COVID-19 clinical trials, or on the websites of various institutions including universities that may be conducting trials.

One has to be screened for whether they are appropriate candidates for the trials, Dr. Parikh said. Usually, the very early phase includes “very healthy” volunteers, often those with few medical problems and within a certain age group. Those interested in signing up for trials must make sure they can invest the amount of time each of them may require.

“The plan is we’re going to be targeting groups in an unprecedented way.” Reaching out to high risk communities, and marketing the studies even though pharmacies and social institutions.

As studies go into large scale testing, companies will have to be very creative on how they can do the various steps involved in the trials remotely, which could mean patients doing swabs themselves, or tests at home; electronic checking in, keeping e-diaries to record how a patient may be feeling etc.

In the study she is involved with, Dr. Parikh said, “We observed that the side-effects were transient, so they would resolve within hours or at most in 24 hours.” No severe or permanent side-effects had been observed, she said.

The Pfizer study may reach the third phase by late summer or early fall, Dr. Parikh surmised. AstraZeneca and Oxford study might also do the third phase in late summer.

As for what can be expected from a vaccine or how long immunity may last, Dr. Parikh said, right now it was a learning curve and researchers and scientists are learning about this new disease. “So time will tell. We are hoping the immunity lasts for a long time.”

The vaccine, Dr. Parikh cautioned, was not the “end-all and cure-all” but rather like other vaccines, it not meant to completely, one hundred percent, prevent the illness. “We still have to continue to be careful.”

“But what we are hoping is that with this vaccine, we can move closer to that herd immunity,” so that way we can move closer to the ‘new normal’, she said.

This virus, has a huge issue of asymptomatic spread, accounting for as much as 50 percent of those who get ill. “The vaccine can help us curb that spread, help us get ahead of it,” help lower the spread, to help guide the reopening process.


As for the fears parents have about sending their children to school, Dr. Parikh said, “The good news is that Pediatric Multi-system Inflammatory Syndrome that we were hearing about — it is still very, very rare in children.”

“… the good news is , with aggressive and proper treatment, even those who developed that rare and severe syndrome, did very well,” she added. “So the overarching theme is again — parents shouldn’t panic because even thought his syndrome is possible, with appropriate treatment, you can get ahead of it. Children do seem to be a little more resilient than adult counterparts,” said Dr. Parikh.

A major characteristic of this virus is its unpredictability, she noted. “But what we know is it affects virtually every organ system,” from the lungs to the heart, the brain, and even the skin. Furthermore, it can cause lifelong health issues. “People have to live with this new normal.”

She recognized ‘quarantine fatigue’ was setting in, “But don’t let your guard down We still don’t have an effective vaccine.” Simple measures can reduce transmission by 70 percent, she said, “So all of us can help save lives.”



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