Source:
NIH Director’s Blog

Credit: Adapted from Pfizer, Dec. 8, 2021

There’s been great concern about the new Omicron variant of SARS-CoV-2, the coronavirus that causes COVID-19. A major reason is Omicron has accumulated over 50 mutations, including about 30 in the spike protein, the part of the coronavirus that mRNA vaccines teach our immune systems to attack. All of these genetic changes raise the possibility that Omicron could cause breakthrough infections in people who’ve already received a Pfizer or Moderna mRNA vaccine.

So, what does the science show? The first data to emerge present somewhat encouraging results. While our existing mRNA vaccines still offer some protection against Omicron, there appears to be a significant decline in neutralizing antibodies against this variant in people who have received two shots of an mRNA vaccine.

However, initial results of studies conducted both in the lab and in the real world show that people who get a booster shot, or third dose of vaccine, may be better protected. Though these data are preliminary, they suggest that getting a booster will help protect people already vaccinated from breakthrough or possible severe infections with Omicron during the winter months.

Though Omicron was discovered in South Africa only last month, researchers have been working around the clock to learn more about this variant. Last week brought the first wave of scientific data on Omicron, including interesting work from a research team led by Alex Sigal, Africa Health Research Institute, Durban, South Africa [1].

In lab studies working with live Omicron virus, the researchers showed that this variant still relies on the ACE2 receptor to infect human lung cells. That’s really good news. It means that the therapeutic tools already developed, including vaccines, should generally remain useful for combatting this new variant.

Sigal and colleagues also tested the ability of antibodies in the plasma from 12 fully vaccinated individuals to neutralize Omicron. Six of the individuals had no history of COVID-19. The other six had been infected with the original variant in the first wave of infections in South Africa.

As expected, the samples showed very strong neutralization against the original SARS-CoV-2 variant. However, antibodies from people who’d been previously vaccinated with the two-dose Pfizer vaccine took a significant hit against Omicron, showing about a 40-fold decline in neutralizing ability.

This escape from immunity wasn’t complete. Indeed, blood samples from five individuals showed relatively good antibody levels against Omicron. All five had previously been infected with SARS-CoV-2 in addition to being vaccinated. These findings add to evidence on the value of full vaccination for protecting against reinfections in people who’ve had COVID-19 previously.

Also of great interest were the first results of the Pfizer study, which the company made available in a news release [2]. Pfizer researchers also conducted laboratory studies to test the neutralizing ability of blood samples from 19 individuals one month after a second shot compared to 20 others one month after a booster shot.

These studies showed that the neutralizing ability of samples from those who’d received two shots had a more than 25-fold decline relative to the original virus. Together with the South Africa data, it suggests that the two-dose series may not be enough to protect against breakthrough infections with the Omicron variant.

In much more encouraging news, their studies went on to show that a booster dose of the Pfizer vaccine raised antibody levels against Omicron to a level comparable to the two-dose regimen against the original variant (as shown in the figure above). While efforts already are underway to develop an Omicron-specific COVID-19 vaccine, these findings suggest that it’s already possible to get good protection against this new variant by getting a booster shot.

Very recently, real-world data from the United Kingdom, where Omicron cases are rising rapidly, are providing additional evidence for how boosters can help. In a preprint [3], Andrews et. al showed the effectiveness of two shots of Pfizer mRNA vaccine trended down after four months to about 40 percent. That’s not great, but note that 40 percent is far better than zero. So, clearly there is some protection provided.

Graph showing Pfizer booster is about 80% effective after 2 weeks against Omicron

Credit: Andrews N, et al., KHub.net 2021

Most impressively (as shown in the figure from Andrews N, et al.) a booster substantially raised that vaccine effectiveness to about 80 percent. That’s not quite as high as for Delta, but certainly an encouraging result. Once again, these data show that boosting the immune system after a pause produces enhanced immunity against new viral variants, even though the booster was designed from the original virus. Your immune system is awfully clever. You get both quantitative and qualitative benefits.

It’s also worth noting that the Omicron variant mostly doesn’t have mutations in portions of its genome that are the targets of other aspects of vaccine-induced immunity, including T cells. These cells are part of the body’s second line of defense and are generally harder for viruses to escape. While T cells can’t prevent infection, they help protect against more severe illness and death.

It’s important to note that scientists around the world are also closely monitoring Omicron’s severity While this variant appears to be highly transmissible, and it is still early for rigorous conclusions, the initial research indicates this variant may actually produce milder illness than Delta, which is currently the dominant strain in the United States.

But there’s still a tremendous amount of research to be done that could change how we view Omicron. This research will take time and patience.

What won’t change, though, is that vaccines are the best way to protect yourself and others against COVID-19. (And these recent data provide an even-stronger reason to get a booster now if you are eligible.) Wearing a mask, especially in public indoor settings, offers good protection against the spread of all SARS-CoV-2 variants. If you’ve got symptoms or think you may have been exposed, get tested and stay home if you get a positive result. As we await more answers, it’s as important as ever to use all the tools available to keep yourself, your loved ones, and your community happy and healthy this holiday season.

References:

[1] SARS-CoV-2 Omicron has extensive but incomplete escape of Pfizer BNT162b2 elicited neutralization and requires ACE2 for infection . Sandile C, et al. Sandile C, et al. medRxiv preprint. December 9, 2021.

[2] Pfizer and BioNTech provide update on Omicron variant . Pfizer. December 8, 2021.

[3] Effectiveness of COVID-19 vaccines against the Omicron (B.1.1.529) variant of concern . Andrews N, et al. KHub.net preprint. December 10, 2021.

Links:

COVID-19 Research (NIH)

Sigal Lab (Africa Health Research Institute, Durban, South Africa)

The COVID-19 pandemic has brought a radical shift in the work environment, resulting in increased number of people around the world working from home or other locations away from their official work space.
MITU did not lag behind in protecting its staff from the spread of the pandemic and allowed a vast majority of staff to work from home. Fortunately, the technology and the available ICT infrastructure at the Unit supported this move and helped the remote working staff remain connected and productive.
MITU is connected through fibre internet – a broadband connection that uses fibre-optic technology to provide fastest speeds data over greater distances without major lag time. With such infrastructure in place, staff are connecting to box drive (a cloud storage service) with ease enabling them to share documents remotely from anywhere anytime. With laptop computers, USB speakerphones, headphones and the internet, staff have been able to stay connected and maintain workflow continuity and conduct live meetings and presentations using Zoom – a video conferencing web platform.

With a virtual private network (VPN) connection – a secure tunnelling technology, staff have been able to securely access the Unit’s local resources from the unsecure public internet by connecting from outside MITU. Remote support tools have also enabled the IT technicians gain access to the remote laptops used by staff working from home and provide technical support in cases of need.

The COVID-19 pandemic has unleashed the new ways in which ICT could support remote working arrangements and allow organizations to remain productive during these challenging times.

Today, both for-profit and non-profit organisations have recognised the value of collaborations. Collaboration among researchers ensures that their knowledge, skills, and techniques are shared, and this could benefit people who participate in the research. The more researchers collaborate, the greater are the chances for success in finding solutions for major global health problems.

In line with its mandate, MITU collaborates closely with a number of local, regional and internationally leading research and academic institutions. The most recent collaboration is with Ludwig-Maximilians-Universität (LMU) Munich in Germany. This collaboration was initiated by Prof Heidi Stöckl who recently moved to LMU, together with her ongoing collaborative research projects with MITU, after twelve years of service at the London School of Hygiene and Tropical Medicine (LSHTM).

This move has created an opportunity for MITU to collaborate with LMU in an ongoing longitudinal study on intimate partner violence in Mwanza, Tanzania. Prof Stöckl and Dr Gerry Mshana at MITU are leading this research. Prof Stöckl said this research ‘’is one of the few longitudinal studies that can investigate change in intimate partner violence and its risk and protective factors over time, therefore providing crucial information on how to prevent this form of violence against women in low and middle income countries. At the same time, our cross-sectional survey of young men is quite crucial in this field, where little is known about young men and the reasons for perpetrating violence or experiencing violence themselves’’.

While this new collaboration is currently focused on completing the ongoing research study, more collaborative opportunities between the two institutions are expected in the future

Studies have shown that high blood pressure (BP) among children and adolescents is relatively common, although only a few have been conducted in Africa. Scientists from the Mwanza Intervention Trials Unit (MITU) recently published a report in the journal of Scientific Report – Nature which shows that adolescents with high BP in Tanzania can be identified in school settings and linked to routine health care services. This study was conducted in 2018 among 500 students aged between 11-15 years from three public secondary schools within Mwanza city.

The report published was based on the study aimed to describe the procedures which could be used to accurately measure BP among adolescents and to determine the burden of high BP in this population. The study involved taking BP measurements using an automatic digital BP machine at three different occasions spaced at an interval of more than a month. Participants with sustained high BP had their BP status confirmed using a portable BP machine programmed to automatically record BP measurements every 15 minutes over 24 hours.

Dr Mussa Kelvin Nsanya – a researcher at MITU and the study lead author – said that, “Adolescents with high BP in Africa can be identified using multiple BP measurements taken at multiple steps in a span of days to months followed by a 24-hour BP monitoring for confirmation. In addition, schools could save as an effective platform for screening of high BP and raising awareness to cardiovascular diseases”.

Findings from this study showed that 50 out of 500 adolescents (10%) had sustained high BP on repeating BP measurements at three different occasions. Using BP measurements taken over 24 hours, investigators of this study confirmed that 13 (2.6%) adolescents had high BP. MITU scientists are continuing to follow-up participants enrolled in this study in order to identify those with high BP and examine factors related to long-term changes in BP measurements.

MITU in collaboration with the London School of Hygiene and Tropical Medicine and Ludwig Maximilian University of Munich, Germany has received funding from the European Research Council to conduct a study among 1,000 young men aged 18-24 years in Mwanza city, Tanzania. The purpose of this study is to investigate the patterns and factors that cause intimate partner violence in the study population.

Between June and December 2021, young men from 24 streets across the city will be invited to take part in the study and those who agree to participate will be interviewed. A team of 9 researchers is carrying out the survey in the streets located in 6 wards in Nyamagana and Ilemela districts of Mwanza city. The interviews cover a range of topics about the lives of these young men and their views and understanding of the different forms of intimate partner violence, its causes and possible ways for preventing it.

The interviews are carried out using hand held computer tablets – a modern data collection technique. In some parts of the interviews, the young men are given the tablets and head phones to listen to the questions and enter the responses by themselves. This ensures that they are part of the research process and safeguards the confidentiality of their responses.


Dr. Gerry Mshana, a senior researcher at MITU and lead scientist for this study said: “Intimate partner violence is a major problem hindering the health, wellbeing and development of children, young people and adults in Tanzania and other parts of the world. We are very pleased for the opportunity to carry out this important and unique study to generate evidence from young men in Mwanza on the magnitude of the problem and their views about it. The results will increase our understanding of the problem and help in designing appropriate interventions and policies in Tanzania and in other similar low-income countries.”

On 26 May 2021, MITU started conducting a survey to collect data that will help to evaluate a reproductive health programme known as “Adolescent 360” or A360. The A360 programme was implemented by the Population Services International (PSI) in 10 regions in Tanzania mainland, including the Mwanza region, and was targeting girls aged 15 to 19 years.

The survey is being conducted in 15 wards of Ilemela district in Mwanza city. In each ward, two streets will be selected by lottery to participate in the study and later visited by trained female research assistants to identify households with girls aged 15 to 19 years. Once this exercise is completed, female research assistants will visit the homes of identified girls to inform them about the study, obtain their consent to participate in the study, and conduct a detailed interview in a private location. Research assistants will also separately interview a sample of adults who live with the interviewed girls. MITU would like to find out whether the A360 programme helped to improve what girls’ knew about family planning (ways to delay or prevent pregnancy), and whether the programme made it easier for girls’ to use family planning services if they wanted to avoid or delay getting pregnant.

More than 5,000 girls will be involved in this survey which is expected to be completed by the end of September 2021. MITU received funds to conduct this survey from the Bill and Melinda Gates Foundation and the Children’s Fund Foundation.

On 11^th May 2021, a group of 10 second year undergraduate sociology students from St. Augustine University of Tanzania (SAUT), Mwanza branch visited our unit as part of the study tour. These students’ interest was to understand the contribution of the Mwanza Intervention Trials Unit (MITU) in solving public health problems.

After an official introduction and tour of MITU facilities, the group was invited for a discussion led by three scientists within the unit: Dr Elialilia Okello (Senior Social Scientist), Dr Kenneth Makata (Public Health Specialist) and Onike Mcharo (Social Scientist). The discussion adhered to proper COVID-19 preventive measures. During the discussion, students were given information about a range of research studies conducted in the Unit.

The students had a chance to ask questions to the researchers about MITU’s contribution in addressing public health problems. At the end of the discussion, the students provided positive feedback on their understanding of MITU’s roles and its contribution towards solving public health problems in the region.