At the World Vaccine Congress in Europe 2022 we will hear from Professor Carlos A. Guzman, head of Vaccinology and Applied Microbiology at the Helmholtz Centre for Infection Research in Germany. He is also APL professor at the Hannover Medical School. We were lucky to connect with him before the Congress to learn a bit more about what he’s working on, and why it’s so important.  

Adjuvant advances

Professor Guzman and his team have discovered new adjuvants, so we wanted to find out a bit more about the importance of identifying new adjuvants, and what his team looks for in a successful candidate. Prof. Guzman emphasised the importance of incorporating adjuvants in subunit vaccines to “improve immune response strength, quality, and breadth”. Furthermore, he stated that their role extends to “reducing antigen dose and promoting long lasting memory”. However, few are available, particularly “those with a well-known mode of action”. Prof. Guzman also identifies a gap in mucosal adjuvants that can “promote immune responses at both mucosal and systemic level”, conferring protection not only against disease, but also transmission. 

“A good adjuvant should be active in all subpopulation groups and exhibit an optimal safety/activity profile, promoting both a self-limited immune activation and a predictable immune protective response.”

Laser-guided weapons against infection

In the past adjuvants have been described as a “sort of witches brew”, but for Prof. Guzman things are more specific and specialised than that. He suggests that “current advances on the molecular basis of innate and adaptive immunity left behind empiricism”. For him, the new generation of adjuvants with “well-defined molecular targets” represents “laser-guided weapons to fight infection”. This is possible because of “selective activation of what is needed” according to “clinical needs”.  

Prof. Guzman also commented on technological developments in his field: “we have moved into the mechanistic arena”. As he is cautious of a “pill/vaccine fits all approach”, he believes that we will be able to “dissect differential responsiveness to vaccination at the level of subpopulation groups or even the single individual”. 

“Genomics brought reverse vaccinology, making antigen discovery programmes more rapid, effective, and simple. I see now a tremendous potential in the area of personalised or stratified vaccination.”

Furthermore, “therapeutic vaccination for infectious diseases” is appealing to Prof. Guzman as a “promising” development to be made, both as a stand-alone intervention or in combination with “anti-infectives or biologicals”.  

Investing in influenza

Prof. Guzman will also deliver a session on influenza vaccine responses in elderly populations. We asked him about the challenges that the recent COVID-19 pandemic has presented, and if there have been any positive opportunities. He recognises several “roadblocks”: 

  • Restrictions in mobility affected training and exchange in international networks 
  • Shortage in material posed a challenge both in research and manufacturing 
  • Operational downscaling and prioritisation of COVID-19 related activities affected other running projects 

However, amidst these disruptions and difficulties, “preparedness plans for influenza represented a cornerstone for evolving improved plans for COVID-19.” Furthermore, we saw a “significant drop in influenza infections” due to “physical distancing measures”. Alas, this might be a short-term change, as Prof. Guzman believes that this might result in “more severe seasonal outbreaks” in upcoming influenza seasons. 

Reflecting on the differences between COVID-19 and influenza, Prof. Guzman pointed out that “in contrast to influenza we have not observed a huge difference in the immunogenicity and efficacy of COVID-19 vaccines in young versus elderly.” However, he reminds us that with the exception of infants, for most individuals influenza vaccination is a booster.  

“Beyond immune senescence and comorbidities or therapies, factors such as immune imprinting play an important role in the outcome.”

Prof. Guzman is keen to understand if this will be problematic in the future, if COVID-19 evolves as a “persistent endemic disease”.  

Another risk for the future is vaccine uptake after we have been potentially overwhelmed by vaccines during the pandemic. Prof. Guzman hopes to impress upon us the importance of vaccines: 

“Vaccines prevent deaths, human suffering, and sequels resulting from infections, as well as huge direct and indirect costs.”

For influenza, he reminds us that there are “approximately 3-5 million cases of severe disease and 1 million deaths worldwide” each year. If that isn’t cause for concern, he also refers to the overwhelming seasonal costs. Furthermore, conservative estimations suggest that there would be “at least a 2% GDP loss per year in case of a new flu pandemic”. Although we know that the influenza vaccine also offers a reduced death risk “in patients affected by other non-communicable diseases”, vaccination coverage in “at risk groups is still suboptimal”.  

Maintaining momentum

We asked Prof. Guzman what he thinks about the importance of keeping a steady rate of progress for responses to familiar pathogens, even as we continue to experience novel threats. Once again, he pointed to vaccination: “we cannot lower our guard in currently running and successful vaccination programmes”. He suggests that we need to learn from past experiences with diseases like polio or measles, although current events would suggest that this lesson hasn’t quite been understood.

He also believes that we can push to develop vaccines for the many infectious diseases that don’t yet have a successful candidate. He considers those caused by “intracellular pathogens causing persistent infections (e.g., HIV, HCV, Chlamydia)”. More work should be also done to improve available vaccines, like those for TB or influenza.  

Prof. Guzman admits that we are going to face “emerging and re-emerging diseases”. Factors such as “global climate change, increment in mobility, and our close contact with animals” mean we must be prepared. He refers to COVID-19 as he warns that “infectious diseases do not respect borders”.  

“Updated preparedness plans, manufacturing capacity building, and equitable plans to make accessible vaccines at a global scale are mandatory…ensuring that, regardless of their income, all individuals have access to vaccines is of the essence”.

Vaccine challenges

When we asked Prof. Guzman to consider the challenges facing the scientific community, he responded that “beyond a fair, equal, and global access to vaccines, we need to maximise vaccine acceptance”. His suggestions on how this might be achieved include providing “adequate information to the public” and pursuing “needle free vaccination approaches” to increase acceptance. Furthermore, he hopes to see products that “exhibit optimal safety/reactogenicity profiles”.  

Whilst informing the public, Prof. Guzman highlights the need for “openness, lack of ambiguities, and consensus between experts and policy makers”. He believes that “risks and benefits” should be clear to the public, and carefully weighed by those in charge of making recommendations; where more than one class of vaccine is available the best match should be found.  

Looking to the future

Prof. Guzman’s response to our question about future public health threats reminded us that it won’t be a simple problem with a simple solution. He warns that there are “far too many problems” with different effects everywhere. One example might be countries with “inverted population pyramids”. For them, the “ever-expanding costs” associated with medical care are difficult to afford. Thus, “healthy ageing” is a key target.

On the other hand, Prof. Guzman identifies “less glamorous prophylactic measures, such as clean water and sanitation”, as having a “dramatic impact” on public health. He also says that we have “just realised” the dramatic human and economic costs of a pandemic, so being prepared for the future “is a must”. 

Thank you to Prof. Guzman for his time and insight ahead of his sessions at the Congress in October. If you still haven’t got your tickets to attend, click here!