There is much noise about vaccines the past few days. Online tension was particularly high following Presidential Spokesperson Harry Roque saying Filipinos may not choose the brand of Covid-19 vaccine they want since so many need to be vaccinated.
Meanwhile, the public seem to be one in saying they have the right to be choosy since it’s their bodies involved here and their lives at stake. Connected to this is the suspicion and criticism surrounding the China-made Sinovac and it’s efficacy. The drug is said to be the first batch of Covid-19 vaccines arriving in the Philippines.
People—experts, ‘feeling’ experts’, and non-experts—have a ton of things to say, and there’s just too much (mis)information going around you don’t know what to believe in.
Dr. Edsel Maurice Salvana says it might be a good idea to “step back and take a deep breath from all this noise.” In his very timely post Wednesday, the infectious disease expert says that the vaccine confidence of Filipinos continues to plummet because of the “non-scientific and non peer-reviewed data circulating around.”
Dr. Salvana, also a molecular biologist, is warning the public against hype. “Science by press-release is the antithesis of true science. True science is carefully looking at the data, analyzing and reanalyzing what's going on, and deciding on how best to move forward. We need to act on data with cold objectivity, not speculate on motives or political intentions.”
Dr. Salvana explains that vaccine efficacy is measured in many ways—“it can be prevention of any infection (both symptomatic and asymptomatic), disease (symptomatic infection), and severe disease.” They can be “transmission-blocking” (vaccines that prevent infection) or “disease-modifying” (vaccines that prevent severe disease). He says most COVID-19 vaccine trials measure both outcomes.
He adds that while the ideal vaccine will prevent any infection, this is very difficult to measure as this requires swabbing those inoculated periodically, whether or not they have symptoms. “So far only the Moderna trial has attempted this, and while their clinical efficacy is 94%, the transmission-blocking efficacy seems to be only about 2/3 effective - which is excellent but less than the clinical efficacy.”
Dr. Salvana says each vaccine will be judged on its ability to prevent infection, clinical disease, and severe disease. Hence, “a vaccine that has UNKNOWN ability to prevent transmission, 62% ability to prevent clinical disease, but 100% ability to prevent SEVERE disease is STILL VERY USEFUL.” Such is the efficacy of the Astra Zeneca vaccine which has been approved for use in the United Kingdom.
As for Sinovac, the vaccine from China, Salvana says there is a need to review data on its efficacy to prevent infection, clinical disease, and severe disease. “If this vaccine prevented only 50% of clinical disease but prevented 100% of severe disease, I would take it.”
He points out that Pfizer is 95% clinically effective but only 89% effective for severe disease. “This is GREAT data, make no mistake. This is why every country will need to have REAL EXPERTS review the data for the FDA before considering use.”
Dr. Salvana urges the public to “Please STOP attacking vaccines.” He says declaring a vaccine as useless, without considering all possible outcomes could be detrimental and “WILL COST LIVES.”
He advises the public to leave it to the Food and Drug Administration (FDA) and the vaccine expert panel to decide which vaccines will be useful to the Filipino people. “The most important thing is to prevent deaths, and any vaccine that can do this is more than welcome. Let's stick to the science and ignore the noise,” he says.