Dear Editor,
On Feb. 4 and Apr.15 (2021) I wrote letters in this newspaper explaining how vaccine efficacy in clinical trials (not to be confused with real world effectiveness) is determined and advised that it’s a waste of time to sit around waiting on a vaccine that you deem ‘superior’ based on these numbers since these numbers can change (and have done so now) when the virus mutates (as it does naturally).
Vaccines are designed against a specific strain/variant since they are based on the genetic sequence of that specific strain/variant. Any change (mutation) in this genetic sequence translating to a change in properties of the virus will change efficacy and effectiveness numbers. All vaccines in use are based on the original strain of the virus. This strain is nonexistent now, replaced by variants including the dominant and dangerous Delta variant, an emerging Epsilon variant and the Gamma variant still prevalent in some places like Brazil where it was first detected. Modifications of vaccines are being done but a modified product must go through clinical trials again. (By the way, contrary to the belief of some, clinical trials/testing of COVID vaccines are no different from any other vaccines. Actually, these are the most scrutinized vaccines in history because, basically, we know better and have better regulatory systems in place than in the past; we have more data to scrutinize now than any other time in history.)
Israel has one of the world’s highest vaccine coverage for COVID – 78% of their population over 12 fully vaccinated, mainly with the Pfizer-BioNTech vaccine. Even with this high vaccine coverage, Israel currently has one of the world’s highest infection numbers with about 650 new cases daily per million people; 99% of these infections attributed to the Delta variant. A high proportion of these infections are in the vaccinated resulting in Israel becoming the first country to offer a booster shot to people as young as age 50. Before the Delta variant the Pfizer vaccine was 95% effective with two doses. Now it varies, depending on the proportion of different variants present. Israel’s Ministry of Health reported in June a 64% effectiveness with two doses, but recently reported a lowering to 39% and as such adjusted their vaccine policy to offer the third shot. This does not mean the vaccines aren’t working. The problem is the new properties of the Delta variant; a variant which arose due to low vaccine coverage. Remember, it emerged in India when their vaccine coverage was less than 4% of their population having received just a first dose – millions were infected, hundreds of thousands died, oxygen was in very short supply, hospitals were overwhelmed and crematoriums were at full capacity. This is why public health officials urge vaccination across the globe, ASAP – to reduce the likelihood of other variants and that health care systems are not plunged into crisis if a worse form emerges.
Israel has a robust public health infrastructure where its entire population (9.3 million) is enrolled in their health maintenance organization which allows them to track how well the vaccines are working. They do a pretty good job of producing quality real-world data that is made available for public scrutiny. Scientists at their Ministry of Health recently published a report that showed protection from COVID-19 infection during June and July correlated with the length of time since the individual has been vaccinated. People vaccinated in January had a 2.26 times greater risk of getting infected than those vaccinated in April (note – the oldest and most vulnerable people were vaccinated first). In addition to this, infections due to the Delta variant have been doubling every two weeks from June to July (Image shows the Delta variance rose to dominance from May 31 to July 26). So, Israel’s problem is attributed to a combination of the Delta variant and waning immunity hence their introduction of booster shots. They have now administered 1 million third doses to people 50 and over despite calls from the WHO director general not to administer boosters given that less than 2% of low-income countries have been vaccinated; leaving high levels of unvaccinated globally is a recipe for more variants (common knowledge by now). Israel’s officials say that boosters aren’t the only thing that will tame the spread of this highly contagious variants; boosters will help relieve the pressure on the health care system. They emphasized the need to vaccinate those who haven’t received first and second doses and to return to masking and social distancing, which they have reinstated.
So, assigning superiority to a vaccine is not going to get us out of the pandemic. We are in a dynamic situation where policies need to be constantly adjusted with new epidemiological data. To get out of the pandemic, we must use the tools at our disposals faster than the virus can change. It means most must be vaccinated before we end up with a virus that renders vaccines completely ineffective. Then that ‘superior’ vaccine you were waiting on would have become useless and you would have aided in prolonging the pandemic. If we forgot what happened in India with the Delta variant then just look at Israel currently. It clearly indicates that we are in a race with a changing virus and possibly waning immunity so the only way we’re going to get the best out of available vaccines is as a collective. Remember, the goal of vaccination is to get immunity at community and population levels because this is what will reduce the spread and reduce the chance of the emergence of worse forms of the virus. It’s everyone’s problem (globally). Most need to get vaccinated and we need to ensure that other measures are not relaxed prematurely (easing up on restrictions too soon also contributed to the crisis India had when the Delta variant emerged). A changing virus necessitates caution on every front. The pandemic is far from over.
Sincerely,
Jacquelyn Jhingree, PhD
