CDC at the frontlines of TB research in Kenya: a conversation with Kayla Laserson

Contributions in this post were also made by Dr. Kevin Cain, CDC Branch Chief for TB at KEMRI/CDC. Click here to read more about Dr. Cain’s work in Kenya.

What got you interested in working with the CDC?

I was getting my master’s at the time in Tropical Public Health at the Harvard School of Public Health, and I remember someone telling me informally that there was this Epidemic Intelligence Service (EIS) program at the CDC. I thought it sounded just like what I’d like to do – and they said you have to be a PhD or an MD and I kept that in the back of my head. I ended up going on to get my PhD, and I never forgot about the EIS program, so when I was ready I applied to the program. It was sort of random – I hadn’t known about it beforehand.

When did you first start working in Kenya? Have you always worked at the Kenya Medical Research Institute (KEMRI) in Kisumu while in the country?

When you first start working at the CDC, it’s almost like a medical school “match.” Imagine a big, intense cocktail party over a week. You go to Atlanta and you interview with a bunch of different CDC programs with different disease foci – malaria, polio, etc.  Then you rank the programs in order of where you would most like to work, and they rank you. If you’re very flexible it works out great – if you’re happy to work in five or six programs, you’re likely to get one of them.

At the end there is a computer match, and I matched with the International TB Program. A couple of months later, I was down in Atlanta working as part of the team, doing various things. A lot of the work in this program is done with the ministries of health, the national TB programs in other countries, and you do a lot of operational research, looking at best practices and improving TB control practices in-country.

I was travelling 30 to 40 percent of the time, sometimes more, which is quite a lot. I went to a number of different countries and I’d stay for a week to ten days each time. I had learned Spanish after college and during my PhD so I worked a lot on the U.S./Mexico border as part of a large initiative looking at TB on the border, and patient care and management as they crossed the border. In Vietnam, I worked on screening and management of TB among immigrants coming to the U.S.  I also did some work with drug-resistant TB in Latvia and Russia, where it was beginning to become problematic. As the U.S. President’s Emergency Plan for AIDS Relief (PEPFAR) rolled in, our branch started working increasingly more with them on TB/HIV co-infection. In total I was there about ten years.

My family and I had been discussing overseas opportunities at CDC, because the travel demands and the time away from home that my job demanded was getting harder to manage. We were looking for overseas opportunities and the job in Kenya had an HIV, TB and malaria focus – and my PhD had been in malaria so I had worked with the three big diseases – so I applied and was accepted.

There are a lot of people here in Kenya with the CDC, but I didn’t really know Kenya or this field station before I came. I’m located in Kisumu – the hub of the KEMRI /CDC collaboration. That was always my assignment to oversee the work here.  The bulk of the work that the CDC does in Kenya is with KEMRI, which is part of the Ministry of Health (MOH).

What are the latest projects going on at KEMRI/CDC?

Besides the TB work, there are about 60 other research projects that are ongoing here. I am involved in some aspect of each of them in one way or another, ensuring they don’t have any obstacles in being executed.

We are one of the trial sites that participated in the NIH-funded HIV Prevention Trials Network (HPTN) 052 trial, which found that treating a person with HIV infection earlier with antiretroviral therapy reduces their chance of sexually transmitting the infection on to their HIV-negative, stable partner by 96 percent. That trial is ongoing.

We also have a number of studies looking at new drugs or new strategies to prevent malaria in pregnant women, side effects of drugs, that kind of thing. For instance, women with HIV that are taking cotrimoxazole can’t take the typical antimalarial drug Fansidar to prevent malaria in pregnancy because of drug-drug interactions. There has been a concern that if pregnant women can’t take Fansidar, is taking cotrimoxazole enough? At KEMRI/CDC, we’ve been looking at whether taking mefloquine on top of cotrimoxazole in HIV-infected women is more efficacious than cotrimoxazole alone?

What is the health and demographic surveillance system (HDSS)?

The HDSS is not a study in itself, but it is a platform where we follow 220,000 people. Every four months we go to their homes, we ask if anyone was born or died since the last visit, what the circumstances of death were, we ask about migration and education, etc. We’ve also gone to those same households and conducted house to house HIV counseling and testing. We have a lot of information on this population. For example, now that the pneumonia vaccine (PCV10) has been introduced by Kenya’s Ministry of Health (MOH) as part of routine vaccinations, with the HDSS we can measure the uptake and impact of the vaccine in the population.

Also, PEPFAR has scaled up ART immensely in Kenya – with our HDSS we can measure the exact scale up. As we have rolled out ART in the HDSS population through PEPFAR, we have seen an almost 30 percent drop in HIV/TB mortality for individuals at the population level – which is not surprising but extremely useful for our MOH to know and use. The HDSS allows us to have a base line and assess the impact of an intervention.

Tell me about the tuberculosis vaccine trial you recently launched.

KEMRI/CDC in Kisumu is one of several sites enrolling infants in this new study designed to test the Aeras 402 TB vaccine. The first phases of the study are complete, and have enrolled 200 infants in three sites in sub-Saharan Africa (SSA).  Based on data from these patients, the vaccine was found to be safe and well-tolerated in infants. In late January we started enrollment of Phase IIB, which will eventually involve up to 4,000 infants at up to four sites in SSA. This trial is designed to see how well the vaccine works and see if it does prevent TB.

During the first phase we enrolled about 70 percent of the infants here at KEMRI/CDC. During this next phase it’s not clear how many we will enroll, but we expect enrollment to be high, maybe around 1,000 but there are no quotas.

When enrollment across all sites reaches the target of 4,000 infants, enrollment will end. The enrollees will be given two injections of vaccine, one month apart, and they will be followed for a period of at least two years. Phase IIB is funded through two sources – Aeras and the European and Developing Countries Clinical Trials Partnership. The U.S. government however is contributing substantially to the effort by having the platforms where a study like this can take place – so it’s one of those situations where it is mutually beneficial. The places where TB is most problematic tend to be the same places where limited resources and poor infrastructure make it difficult to do a sophisticated study. KEMRI/CDC has a long history of conducting complicated studies in Kenya.  So in this situation, Aeras benefits by having a site where the vaccine can be tested and tested well. The U.S. benefits through participation in a study that has potential benefit to the U.S. without having to be the sole funder. The majority of cases of TB in the U.S. come from people born outside of the U.S., so the key to controlling TB domestically will be controlling it globally. A vaccine would go a long way toward achieving this goal.

The CDC has been investing in the KEMRI/CDC collaboration for 32 years. So the investment in the buildings, the laboratories, the road network we travel on, the facility upgrades, were all long-term investments over the last 32 years. Now a lot of outside founders – The Gates Foundation, Aeras, etc – see a benefit of investing in the already existing infrastructure and leveraging the existing U.S. government investments. A lot of the things being done, like vaccine trials, are not fundable by the CDC at this moment but benefit CDC – so it’s a nice synergy between CDC and other funders.

We are of course very hopeful that we will find a vaccine that works well. Many people in the U.S., when they think of TB, they think of it as a disease that is gone – that their ancestors had to deal with. In reality it continues to kill about 200 people an hour – a total of about 1.7 million per year. The impact of the disease is just enormous. Finding a safe and effective vaccine that would do a good job of preventing the disease would be the best of all. This is really ground breaking – no vaccine candidate has gotten this far – so it’s really exciting to be a part of what might be a new era. We’re at similar points with a malaria vaccine (RTS,S), here again we are testing the only vaccine to make it this far, which has thus far shown a reduction in clinical malaria by 50 percent in 5-17 month old children.

We’re also doing some work on a new TB regimen through the TB Clinical Trials Consortium (TBTC), which is a network of about 20 trial sites hosted out of CDC, Atlanta. It looks at finding new, better treatments for TB. KEMRI/CDC is now one of those sites. Just last week we started enrolling patients in a study of a drug called rifapentine to see how well that works in TB treatment. The goal is really to find a shorter TB treatment. Right now, TB treatment involves six months of therapy with up to four drugs per day. That’s really a lot to ask of anyone, so the goal is to find something that works just as well but is shorter.