President Yoweri Museveni asked Ministry of Health experts, scientists six key questions that will guide whether the lockdown is lifted or not.
Here we reproduce Museveni’s questions and answers from scientists….
Have we removed all the virus from the population? If NOT, where is it? How do we handle it?
We cannot say, with confidence that we have removed all COVID-19 infected people from the population. Based on the evidence, we believe that the potential for ongoing infections does exist through contacts of some of the truck drivers and cross border movements beyond the truck drivers.
The populations in the districts at the border entry points and Ugandan officials who interact with the truck drivers at entry points as well as populations along the major highway where they stop for services, are particularly at risk.
Finally, it’s also possible that contacts contacts of some of the contacts of the initial air travelers could have escaped undetected, since this is a disease with about half of the infected individuals do not show symptoms.
The Ministry of Health has commissioned a systematic community risk-assessment study to evaluate potential for ongoing community transmission. This study will sample the high risk populations listed above, among others and test them for COVID-19 using the current PCR tests and antibody tests that can detect previous exposure. The preliminary results of the survey are due in 10 days from now (1 day before the end of the current lockdown period).
Further, through the existing sentinel surveillance sites for influenza like illnesses across several health facilities, we will also he able to capture any unusual occurrence of respiratory Infections and be able to test those who present with COVI like symptoms.
There are efforts to further strengthen this system.
One important issue we need to be aware of and plan for, is that SAR-Cov-2 the virus that causes COVID-19 is a new (novel) virus and all of us are potentially not immune. As long as other countries have the disease, even if Uganda has eliminated it, we will remain at risk.
Until a vaccine is available, the disease will therefore be with us for a long time and may cause repeat infections like has happened with the SAR Cov-1 and other influenza infections.
Several of these infections often cause waves of outbreak, especially when a vaccine is not available and many people with in the community remain vulnerable. It is therefore important for us to have a long-term plan to control community transmission and to prevent importation of the disease.
The potential to have a build up of cases does exist and thus requires further strengthening our surveillance systems and healthcare for long-term management of those who are infected.
How do we protect the population when we lift the lockdown?
The only sure-way to protect the population, completely would be through_, vaccination, however we currently do not have a vaccine. In the absence of the vaccine, -we have other prevention measures, which are often referred to as the non-pharmaceutical interventions (WI).
The commonly used NPI include social or physical distancing, hand hygiene (hand washing with soap and sanitizers), use of masks by health workers and the public, protecting the most vulnerable and keeping them away (e.g. those aged 60 years or older, people with pre-existing conditions such as heart and lung disease, HIV infected people, among others).
Testing, tracking of contacts of infected people and isolation of those who are infected with COVID-19 when widely expanded keeps away those who are infected and limits transmission to more people.
Finally, early and good care for those who are infected with COVID.19 helps to minimize mortality. We get better results when we keep the numbers manageable, within the capacity of the healthcare system. When many people are infected within a shot time, the system is overwhelmed and many people die.
Are Masks useful? What is the science (entire paper)? If yes, what type for the population?
Use of masks by the community is primarily to prevent the spread of the virus by the infected people particularly those that have no symptoms of the infection (source control).
When the people don’t use masks, the virus is seeded into the environment through aerosols, which may directly go to the mucus membranes of the eyes, ears and nose of those who are near them or may settle on several surfaces and eventually infect other people.
Masks therefore reduce contamination of the environment and transmission of the virus. However, it is important to note that masks can only be helpful if used as part of a comprehensive package of control measures. When many people within a community are infected with COVID-19 and there are many shading the virus, the effect builds up and the risk to those who are not infected is high.
Whereas we know from evidence that some types of masks e.g. cloth masks and surgical masks are not as that protective to the person who is not infected, it is not possible to always know who is not infected since about half of those who are infected have no symptoms. The masks are thus very useful in preventing infection especially from the asymptomatic and pre-symptomatic infected individuals.
Ordinary cloth and other suitable material of non surgical masks as well as surgical masks and various types of respirators are protective. The respirators for example the commonly used N-95 are most protective to the user. However, these are often preserved for healthcare workers and individuals nursing the sick patients, who are at highest risk, since we do not have sufficient stock globally and locally to cater for the needs of those who are at highest risk.
How do we stop importation of new infections among cargo-, truck- and train-crew?
Importation of cases can be minimised or stopped when we have an effective program for testing all individuals who enter the country and quickly isolating those who test positive to avoid spreading of infection to other individuals.
Testing at the point of origin and retesting at entry would be useful, especially if results are available before entry to Uganda.
This requires a combined effort of the EAC to ensure a comprehensive regional cross border program such as the programs we previously had for HIV.
Access to and deployment of tests which can provide results within a few minutes helps to ease the process-these tests are currently not widely available, although they are increasingly becoming more available.
In the meantime, the idea of relay drivers could be useful, if it is supplemented by disinfecting the tracks before they are taken over by another driver, and use of protective tools (e.g. masks) by the track drivers.
The struggle to develop a vaccine, how far have we reached? Are we working alone, or with international collaborators?
Globally, approximately 70 COVID-19 vaccine constructs are in development, with six already in early phase in human safety testing and several others likely to enter clinical trials in the coming months.
In Uganda two approaches have been considered:
Using other available vaccines: Ugandan scientists are discussing protocols to test a COVID-19 vaccine in Uganda. There are two potential candidates under discussion at UVRI, one with scientists at Imperial College London who are developing a self amplifying RNA COVID-19 ye etc and another with University of Oxford to use the Cheep-adeno vaccine which is now being tested in the United Kingdom. Two meetings were held last week. The Oxford team wants to move quickly to an efficacy trial and they are more interested in countries with a high number of new COVID-19 infection, which presents challenges since Uganda does not have many new infections.
For the saRNA, they are ready to provide the vaccine free but are looking for funds for a phase Atrial in Uganda.
Ugandan scientists developing a vaccine: No our knowledge is currently developing a vaccine for COVID-19 but there is interest and plans at Makerere University and at Uganda Virus Research Institute (UVRI). On Tuesday next week we will have a meeting at Makerere to exchange ideas and plans. At UVRI there are discussions with Imperial College to use their approach to develop a COVID-19 vaccine—to develop a Rift Valley Fever vaccine using the same approach.
UVRI has generated the sequences for the virus and has held discussions with a manufacturer to explore this option. We are continuing with the discussions with the idea of designing a saRNA vaccine.
We have a PhD student in London using this approach to develop aRFV.
Are we working alone, or with international collaborators?
Vaccine development is a long process and cannot be done without partnerships. We need to make a construct in the laboratory, if it expresses the desired immunogen or protein, test it in small animals for safety and immunogenicity (UVRI will be setting up this facility to house small animals, which was planned before COVID-19). If successful, the tests move into larger animals to perform animal challenge studies to see if the vaccine protects (this requires a P4 facility which does not exist currently). The next step is to start human studies (Phase 1 to phase III/IIB). The vaccines have to be made under good manufacturing practice, GMP. Usually Universities stop at small manufacture and bring in larger companies that can make larger stocks. Thus, vaccine manufacture needs international collaborations.
How are we planning to increase testing? How much testing has to be done at population level to satisfy surveillance?
We have identified populations at higher risk of infection including contacts of COVID-19 infected people, those with respiratory tract infections, frontline healthcare workers and surveillance officers, populations at border entry points and those along the major highways and stopover towns for the truck drivers.
These will be sampled and tested more regularly based on outlined schedules to ensure that those who are infected are quickly isolated to interrupt transmissions.
We will use the current PCR and antibody tests once they are widely available—the antibody tests indicate previous exposure to COVID and can also show who might potentially be protected from infection.
Testing using PCR as we are doing now will only identify those who are still actively shedding the virus (normally initial 14 days) but miss those who recovered. It is also expensive for surveillance for surveillance when a larger number of individuals are tested.
We should ideally increase the number of tests threefold within the next ont-two weeks, and even further to >500,000 tests over the next four months based on our draft model- these numbers will be reviewed and revised once we have the results from are planned community study.
At the moment we are planning to evaluate antibody tests to advise on which ones are best to use. There have been challenges with these tests also called rapid diagnostic tests (RDTs) but good ones are now coming up which we will urgently evaluate. The protocol for evaluation has been given approval by the ethics committee.
When do we say we have herd immunity and people can go back to normal?
Response: When most of a population is immune to an infectious disease, this provides indirect protection—or herd immunity (also called herd protection)—to those who are not immune to the disease. This can be achieved either through vaccinations or natural infection.
The percentage of population level immunity required for a population to achieve herd immunity varies by disease but we anticipate that this would be at least 70%, based on evidence from other related diseases.
However, there is currently no evidence of how long the antibodies to COVID-19 remain protective if at Al. It is thus not clear that herd immunity will be beneficial in COVID prevention et this point, and this is one of the questions we would like to answer. The only sure way of getting herd immunity will be through vaccination, once vaccines are available.
Because we are now implementing lockdown, to prevent transmissions, it will not be possible to achieve herd immunity through natural infections.
On the other hand, allowing many people to get infected when we are not certain that the immunity from natural infection will be protective, would be risky and could result in a large number of infected individuals and many deaths.
We will inevitably have some people infected and potentially immune and eventually through vaccination as the vaccines become available.