A battle between Vaccine and Virus, who wins?

Tel Aviv: The state of Israel made history this month when it undertook a highly complex campaign at top speed and vaccinated 1 million people within two weeks. It is also extraordinary that despite the strict rules to maintain the cold chain, one in 1,000 vaccinations were reduced here; Pfizer’s vaccine should be kept at minus 70 ° C (minus 94 ° F). Many worthy people are responsible for this success. Still, we must not get away and forget that we are in the heat of a race, the results of which have not yet been determined: a local race between the spread and impact of the epidemic collective. Vaccination campaign

Israel is in the midst of the third wave of disease, which is more prone to being aggressive than its predecessors, both due to the winter weather when people tend to spend more time in closed unequal settings, and, as yet unknown range Till, because of the proliferation of the UK version in Israel.

While this variant is not more pathogenic, experts believe that it is more infectious – perhaps 1.5 times more widespread than viral strains – and can significantly alter transmission dynamics. And Israel’s current situation is fragile and risky: worldwide per capita rates have increased gradually in recent weeks.

The onset of winter has seen a rapid increase in illness and death in almost all European countries, including the Czech Republic, Belgium, Sweden, Switzerland, and Greece. All these countries are similar in size to Israel and have seen 80 to 200 deaths per week attributed to Covid. Israel, which already sees 20 deaths a day from coronaviruses, views these countries with concern, trying to deal with imminent effects with two means of intervention: one through currently implemented partial lockdown and one Limiting the spread of the virus through the accelerated mass. -Cleanliness campaign.

Direct vs indirect effect

Vaccination campaigns can alter the consequences of a winter wave of infection in two significant ways: by influencing a severe illness between the virus spreading at vaccination (“direct protection”) and the population level (“indirect protection”). We will try and assess the impact of each of these weapons:

Large-scale Pfizer and Modern studies demonstrated the direct protective effect of vaccines. In Modern research published last week in The New England Journal of Medicine, one of the world’s leading medical journals, 30 cases of critical illness were reported in the placebo group, and zero (!) In the immunization group. It is difficult to recall such impressive results in vaccine efficacy studies.

Nevertheless, at the overall population level, the overall impact of the direct effect of immunization of the elderly is limited. According to Clattal Health Services data, about 80 percent of serious illnesses occur in people 60 and older. A simple calculation would show that the expected 70 percent elderly immunization by the end of this week – 85 to 90 percent of which immunity will develop in a few weeks – would reduce critical illness rates by 50% in infected people.

This is undoubtedly a dramatic improvement, but in itself does not change the game rules – because a doubling of the daily number of new cases, which currently occur every two weeks, will completely negate this beneficial effect.

Even greater expectation lies in the potential for indirect protective effects, ensuring that an ever-increasing proportion of vaccinated individuals hinders the virus’s spread. Thus, if the average patient was expected to infect four people (factor R ‘factor) but encounters a population in which a quarter of people are immune, it will infect only three people. A fourth person, who was not infected with the vaccine, could protect the four people he feared to be infected, although three of those four were never vaccinated.

And that is the indirect effect, which protects the undefined. This effect was demonstrated to save more lives in uneducated elderly than children when children were vaccinated against pneumococcal disease.

Does coronavirus vaccination reduce infection and asymptomatic disease and thus provide indirect protective effects? The answer is not as straightforward as one might think. Applying a vaccine to a muscle, which leads to the formation of cellular immune and type of antibodies that spread to the bloodstream, does not guarantee the appearance of antibodies in the nose and mouth’s mucous membranes, which are necessary to protect the individual a. Mild upper respiratory infections and potentially spread to others. No appropriate studies have been conducted to date to determine whether this is true and to what extent, but a relevant large-scale prospective study is underway at the Clatit Research Institute.

The extent of indirect protective effect depends not only on how many people get vaccinated but also on who gets vaccinated. For example, vaccinating socially isolated adults has less impact than vaccinating those at the center of social networks, as shown in previous studies on influenza. Non-homogenous mixing of vaccines in the population further complicates the evaluation of this indirect protective effect.

We must now, first and foremost, fully vaccinate vulnerable subgroups, as the direct effect is noticeable and not dependent on ever-changing public behavior.

Vaccination of the 20% most vulnerable sections will not allow us to return to the “pre-coronavirus” routine – this will be considered when we reach 70 to 90 percent of the entire population (some through natural infection, and most by . Safe passage of the vaccine), indirect protection will allow for an inherent decrease below 1R, without reliance on any permanent protection. At this point, called “herd immunity,” we can expect to return to regular life almost as it was before the virus.

Questions that will determine how the story unfolds:

Five open questions will determine who will win 2021 between races between the vaccination campaign and the virus spreading in Israel. Mathematical models have produced different results based on the following characteristics in question.

1. Real-life vaccine effects among the elderly

In a recently published Modern Study, efficacy among young people was 94 percent, compared to 86 percent between those 65 and older. These results indicate the need for conservative assumptions of real-life vaccine effectiveness in a campaign that focuses on the most immune-compromised subgroups in cold chains under logical circumstances that may not be true in clinical trials. This focus on this subgroup also serves to suggest against considering the British model of second vaccine supplements.

2. Effectiveness of vaccines in reducing infection and infectiousness to others, thus reducing the R factor
Modern vaccine studies hint at ~ 60 percent effectiveness in reducing disease – which, in my opinion, and is excellent news, is a reasonable work assumption.

3. Effectiveness of current government control efforts

The partial lockdown scheme lacks coherence (restrictions on street commerce closures and businesses away, while 10-person meetings in closed spaces and opening high-school classrooms face the apparent risk of infection). We will begin to see the measurable impact this weekend, and the real concern is that the results will be limited, despite the severe effects on the economy.

4. UK type prevalence rate in Israel

The new version is potentially a game-changer. If and when it becomes a significant strain in Israel, the R factor is likely to increase significantly, regardless of government efforts to investigate the virus. Our mission is to safeguard the national risk mechanisms that occur before facing this challenge’s full force and to protect at-risk populations before they occur.

5. Probably the essential unknown: the rate of vaccines to Israel

Israel received a relatively large initial shipment of vaccines, enabling it with discretionary use to fully cover at-risk populations. There is no way to know when we will receive additional loads and where we will stand at that level in case of the virus spreading. Therefore, we must be cautious about applying the vaccine to its target population – a small group of older people and younger patients with multiple chronic diseases, which places them at exceptionally high risk. We must do so and ignore the background noise, urging us to keep immunization centers active at full cost at all costs, focusing on the total daily number of incorrectly performed vaccinations.

In the choice between a spike rate of vaccination and the target population’s exact choice, we must now choose the exact one. Because if vaccination of young people causes us to be “stuck” for weeks without the ability to vaccinate a high percentage of the risk-free population, the possibility of a vaccination campaign to prevent severe damage from the continued spread of the virus Is likely to be maintained. Mortal shock

Hope clouded with fear

It is a complicated and unstable period in which hope and fear are often interlinked. We have a unique opportunity to avoid the most severe consequences of the winter wave in Europe and the United States, despite the increasing spread of the virus and the more infectious variants already spreading in Israel.

Israel’s health care system should be greeted with gratitude for today’s achievements in this heckling mass-vaccination campaign, but the fight is far from over. We face a difficult, risky phase, with a heavy burden on the health care system and a long period to deal with the dire consequences of long-term damage to our economy.

Vaccination of the older population is not a flak jacket of total protection, which frees us from the need to control viral spread. Until the above open questions are answered, we will not correctly assess the extent of imminent risk in the coming months.

Therefore, even during this vaccination campaign, we must be vigilant and follow the basic rules of personal responsibility: wear a mask, maintain social distance, minimize outside-home contacts, and self-refer whenever there is a sign. Ensure isolation disease. Covid continues to spread rapidly and puts those in danger who have not yet been vaccinated or have developed an immunity.

Many countries are now eyeing Israel as to how the story unfolds here and how vaccination will change the disease’s course. We should expect that in this final chapter of the crisis, we will once again be a role model, as it was during the first wave, not a warning light for the world, as we were in the second wave when we hurried Announces victory in the final whistle.

Content courtesy: Haaretz