This article continues the previous discussion regarding the COVID-19 vaccine. New cases are now reaching record numbers and as variant viruses steadily increase, concern is also rising about the future outlook.

In contrast to this situation in Japan, we can point to the United States and the U.K. As of this writing (March 2021) , new cases in the two countries amount to 50,000 and 5,000, respectively, and although these figures are much higher than in Japan, both countries proudly claim that they will be free of COVID-19 by summer of this year. Perhaps this outlook is a matter of national differences, but Japan's different attitude and outlook can be attributed to the following two points that are at work in the background.

The first is the speed of vaccination. The new U.S. president quickly carried out his political pledge (vaccination of 100 million people in 100 days). On busy days, 3 million people were vaccinated in one day, and 29.2% of the U.S. population has already received the first vaccination. In the UK and Israel, where vaccination was promptly carried out, these percentages are 44.9% and 60.0%, respectively. Japan, however, still lags behind at 0.7%. One might attribute this to the inability to manufacture the vaccine domestically, but among countries with a high total number of vaccination doses administered per 100 people in the total population, the majority of the countries in the top 20 do not manufacture the vaccine domestically. For example, Indonesia with 4.27 doses per 100 people ranks 20th, Hungary with 29.53 doses ranks 7th, and Chile with 54.73 doses is 3rd (as of March 31, ourworldindata.org). While this may be because nations with a high number of cases are given precedence, Japan's delayed response cannot be denied.

Another reason, which is my personal view, is the difference in the messages communicated by the leaders of these nations. Leaders in the United States and the U.K. have been communicating an optimistic outlook that gives hope to their people. In the past, there were also politicians with optimistic messages that were groundless, but today, based on evidence, leaders in the U.S. and the U.K. appear to be reporting a (slightly) bright future to their citizens. In comparison, perhaps to avoid political responsibility, political leaders in Japan tend to exercise extreme caution by carefully avoiding optimistic statements.

Nevertheless, the purpose of this blog post is not a discussion of the above, but rather information on recent vaccines. And this information serves to support the optimistic outlook above.

Current Vaccines Appear Effective on Variants

The efficacy of the COVID-19 vaccine is confirmed by proving that those who have been vaccinated are less likely to become infected by the virus than those who have not been vaccinated. Only half a year has passed since the first group of people received the vaccine right away, so more time is needed before the effectiveness and duration can be verified. Nevertheless, as noted in the New York Times article cited in my earlier blog post, among the 75,000 people in the U.S. who were vaccinated right away, the rate of infection has been very low, which is encouraging data that supports the effectiveness of the vaccine.

Another method to predict the effectiveness of a vaccine is measuring the neutralizing antibodies in the blood after vaccination. Determining this effectiveness is based on test-tube results, but it is possible to predict the actual protective effect with considerable certainty.

Three days before writing this article (March 19), a news flash published in the Journal of the American Medical Association (JAMA) announced the results of a study that measured the neutralizing antibody response to four variants, including the variant originally detected in the UK, which is found to be highly infectious. To state the conclusion simply, blood tests of those who received vaccination (mRNA vaccine) for the four variants of the virus showed a concentration of neutralizing antibodies sufficient to prevent infection by the variants. Concurrent blood tests of patients after infection by COVID-19 indicated nearly the same high concentration of neutralizing antibodies.

It may be premature to link this result to the actual prevention of infection (or a lower infection rate), but the data does heighten our expectations.

Vaccination of expectant mothers creates immunity in both mother and newborn

Recently, another research result has also been astonishing news. As you know, expectant mothers are not included the clinical trials of vaccines for ethical reasons and out of concern for possible effects on the unborn child. (Children are not included either.) In Japan as well, pregnant women are not considered eligible for vaccination.

Under these conditions, in the United States, pregnant women who voluntarily apply are receiving vaccination. Upon reading about the expectant mothers who volunteered, I felt personally moved by their courage.

According to a March 7 update (medRxiv), 131 mothers volunteered for tests to measure specific COVID-19 immunoglobins or antibodies (IgG, IgA, IgM) in their blood, cord blood, and breast milk. The results indicated that in the blood of pregnant women who had received the vaccine, not only had the antibodies increased as is the case in those receiving the vaccine who are not pregnant, but COVID-19 antibodies were also detected in the cord blood and breast milk. As cord blood is equivalent to the blood of the newborn infant, the effect of vaccinating mothers-to-be will also extend to the child who is born.

Based on these research results alone, it is not yet possible to draw a conclusion regarding the effect of the vaccine on the unborn child and related issues, but they may serve as a basis for recommending the COVID-19 vaccine to expectant mothers as well.

• Edara, VV. Et al. Neutralizing Antibodies Against SARS-CoV-2 Variants After Infection and Vaccination. JAMA, 2021
  Doi: https://doi.org/10.1001/jama.2021.4388
• Gray, KJ, et.al. COVID-19 vaccine response in pregnant and lactating women: a cohort study. medRxiv. Doi: https://doi.org/10.1101/2021.03.07.21253094