Pertussis has been known since at least the Middle Ages, although the bacteria that causes pertussis, Bordetella pertussis, wasn’t discovered until 1906.
That discovery led to the later development of the first pertussis vaccines, but before then, pertussis was a big killer, with epidemic cycles every 2 to 5 years.
During one of these cycles in the United States, from 1926 to 1930, there were:
909,705 cases, and
Unfortunately, even natural infection doesn’t provide life-long immunity, so adults would get pertussis and give it to susceptible kids, who were most likely to die during these epidemics.
But even in non-epidemic years, a lot of folks got pertussis. The number of reported cases ranged from “just” 161,799 in 1928 to 202,210 in 1926. And during one of the biggest years, 1934, there were 265,269 cases!
Post-Vaccine Era Pertussis Outbreaks
That changed in the vaccine era.
The first pertussis vaccines were developed in the 1930s and became more widely used in the 1940s when it was combined into the whole-cell DTP vaccine.
This was replaced with the acellular DTaP vaccine in 1997, with the Tdap vaccine being added to the vaccine schedule in 2006.
These vaccines helped to greatly reduce how many people got pertussis and how many people died from pertussis:
1940 – 183,866 cases
1950 – 120,718 cases and 1, 118 deaths
1960 – 14,809 cases and 118 deaths
1970 – 4,249 cases and 12 deaths
1980 – 1,730 cases and 11 deaths
1990 – 4,570 cases and 12 deaths
2000 – 7,867 cases and 12 deaths
2010 – 27,550 cases and 26 deaths
They never eradicated pertussis though, and as you can see, recently, pertussis cases have started to rise again.
In 2012, there were 48,277 cases of pertussis in the United States, the most since 1950, when we had 68,687 cases. Unfortunately, with the rise in cases, we are also seeing the tragic consequences of this disease – 20 deaths in 2012, mostly infants under age 3 months.
Pertussis cases remained steady, but high, in 2013 and 2014, at around 30,000 cases in the United States.
In California, pertussis reached epidemic levels. The California Department of Public Health reported at least 11,114 cases in 2014 – the highest numbers of pertussis cases in the state in 70 years!
And as expected with the rise in cases, there were 3 pertussis related deaths in California that year – all infants who had contracted pertussis when they were less than 8 weeks old. Two of the infants became sick in 2013, but the third, a 5-week-old baby, got infected in 2014.
Another baby, only 25 days old died in early 2015, but will be counted as the 2nd death of 2014 since that is when the illness started. About 383 patients, mostly infants who are less than 4 months old, were hospitalized in California that year, including 80 who required intensive care. And according to the California Department of Public Health, about 82% of the cases in infants were born to mothers who did not receive a dose of Tdap during their third trimester of pregnancy.
What’s happened since then?
Pertussis cases are continuing to fall each year! In fact, with about 16,000 cases in the United States, 2017 may have ended with the lowest number of pertussis cases since 2008.
Still, with just 1,830 pertussis cases in California in 2016, there were two deaths – both infants who were younger than 3 months of age when they got sick. And there was at least one death in 2017, with similar rates of disease, although reports are still preliminary.
Why So Many Pertussis Outbreaks?
Ever since a 2010 California pertussis outbreak, in which there were 9,154 cases of pertussis, the most in 63 years, and 10 infants died, many people, especially parents, began wondering why we were seeing more pertussis these days.
Is it because the pertussis vaccines simply don’t work, as the anti-vaccine movement would have you think?
A commentary, Why Do Pertussis Vaccines Fail?, by James Cherry, MD, gave us some answers.
While the title of the article might have you think that all of the blame lies with the pertussis vaccines, that certainly isn’t the case. While there can be vaccine failures with the pertussis vaccines, just like any other vaccine, that doesn’t mean that the vaccine doesn’t work for most children.
One of the problems is that the DTaP vaccine likely isn’t as effective as the older DTP vaccine. So instead of efficacy of 84 to 85%, as was once believed, it is likely closer to just 71 to 78%.
Other issues, including waning immunity, the possibility of an incorrect balance of antigens in the vaccine that could create a blocking effect, and genetic changes in the B. pertussis bacteria, could also possibly lead to increased vaccine failure rates.
So it isn’t that the pertussis vaccines don’t work.
That should be easy to see when you look at the pertussis rates in California, when the highest rates by far were in infants less than 6 months of age (434 per 100,000 people). In contrast, children who were 6 months to 6 years old had a rate of only 62 per 100,000.
And the results of a study that were presented at the 49th annual meeting of the Infectious Diseases Society of America in Boston show just how important the pertussis vaccine is, as:
vaccine effectiveness was 98.1 percent among children who received their 5th dose within the past year
long term effectiveness – children who were five or more years past their last DTaP dose – was about 71 percent
children who had never received any doses of DTaP (unvaccinated children) faced odds of having whooping cough at least eight times higher than children who received all five doses
It is also important to note that the high rates seen in 2010 in California are still well below the rates that were seen in the pre-vaccination era, when the attack rate of pertussis in the United States was as high as 157 per 100,000 people, with about 200,000 cases a year.
What’s the answer?
“The present “resurgence of pertussis” is mainly due to greater awareness and the use of PCR for diagnosis. There are also many other factors which have contributed to the “resurgence.” New vaccines are clearly needed; with our present vaccines (DTaP and adolescent and adult formulated tetanus and diphtheria toxoids and acellular pertussis vaccine (Tdap)), if used correctly, severe pertussis and deaths in infants can be prevented.”
James D. Cherry, MD on The History of Pertussis (Whooping Cough); 1906 – 2015: Facts, Myths, and Misconceptions
It certainly isn’t for more kids to follow non-standard, parent-selected, delayed protection vaccine schedules or to simply skip vaccines all together. Since natural immunity isn’t going to keep newborns and infants from getting pertussis, the ages which are most at risk for life-threatening infections, they can catch pertussis from people around them, including those working on their natural immunity. Natural infections don’t even provide life-long protection against pertussis, as some people believe. That natural immunity wanes fairly quickly too.
The future of pertussis control is more likely going to be in maximizing our current vaccination program, including getting more teens and adults to get the Tdap vaccine, especially when women are pregnant.
That’s the best strategy, at least until new pertussis vaccines are developed. It provides a lot of benefits. According to the CDC, like with the flu vaccine, when you get a pertussis vaccine, in addition to protecting yourself and those people around you, “people who do catch whooping cough after being vaccinated are much less likely to be hospitalized or die from the disease.”
Unfortunately, not everyone has gotten the message. And because of waning immunity, children who aren’t vaccinated against pertussis can’t “hide in the herd” and rely on the rest of us who do vaccinate our children to provide them with protection. Instead, since they are at a higher risk, they get pertussis and get even more people sick.
In one study, Parental refusal of pertussis vaccination is associated with an increased risk of pertussis infection in children, researchers found that “vaccine refusers had a 23-fold increased risk for pertussis when compared with vaccine acceptors, and 11% of pertussis cases in the entire study population were attributed to vaccine refusal.” The highly contagious nature of pertussis then means every primary case is probably going to infect as many as 17 other people. That’s why it makes sense that higher rates of children using vaccine exemptions could be at least one of the factors in these outbreaks.
In fact, several studies, including, Geographic Clustering of Nonmedical Exemptions to School Immunization Requirements and Associations With Geographic Clustering of Pertussis, found that “geographic pockets of vaccine refusal are associated with the risk of pertussis outbreaks in the whole community.”
Many factors are responsible for the rise in pertussis outbreaks in recent years, but it is clear that being unvaccinated and unprotected put you at greatest risk for getting pertussis and passing it on to others.
We often have to remind people that the anti-vaccine movement didn’t start with Bob Sears, or Jenny McCarthy, or even with Andy Wakefield.
Did you know that the Reverend Cotton Mather’s house was bombed in Boston in 1721? Well, someone through a bomb through his window. Fortunately, it didn’t go off.
That’s 77 years before Jenner developed his smallpox vaccine!
What was Mather doing?
He had started a smallpox variolation program. He was trying to protect people in Boston from smallpox during one of the most deadly epidemics of the time.
So essentially, the anti-vaccine movement started before we even had real vaccines…
Is the Anti-Vaccine Movement Growing?
You see reports of more and more outbreaks of vaccine-preventable diseases, hear about new vaccine laws and mandates, and depending on who your friends are, may see a lot of anti-vaccine articles and vaccine injury stories getting shared on Facebook.
You have probably even heard about pediatricians firing families who refuse to vaccinate their kids.
So what’s the story?
Is the anti-vaccine movement growing?
Is there a growing resistance among parents to getting their kids vaccinated?
“Parents are taking back the truth. It is my expectation that this crack in the dam will serve to sound an alarm. To wake women up. To show them that they have relinquished their maternal wisdom, and that it is time to wrest it back.”
Kelly Brogan, MD
Is the world finally “waking up to the dangers of vaccines,” like many anti-vaccine experts have been claiming for years and years?
The Anti-Vaccine Movement is not Growing
Many people will likely tell you that the anti-vaccine is in fact growing.
You can read it in their headlines:
The worrying rise of the anti-vaccination movement
Will 2017 be the year the anti-vaccination movement goes mainstream?
Pediatricians calling anti-vaccine movement a growing problem
There’s Good Evidence That The Anti-Vaccine Movement Is Growing
I was skeptical that the anti-vaccine movement was gaining traction. Not anymore.
But the anti-vaccine movement is not necessarily growing.
The overwhelming majority of parents and adults are fully vaccinated.
Most parents do their research though, don’t jump on the anti-vaccine bandwagon, and know that vaccines work, vaccines are safe, and vaccines are necessary.
The Anti-Vaccine Movement is Changing
A lot about the anti-vaccine movement hasn’t changed over the last 100 plus years.
Many early critics of vaccines were alternative medicine providers, including homeopaths and chiropractors, just like we see today. And like they do today, they argued that vaccines didn’t work, vaccines were dangerous, and that vaccines weren’t even necessary.
The big difference?
Unlike when Lora Little, at the end of the 19th century, had to travel around the country to distribute her anti-vaccine pamphlet, Crimes of the Cowpox Ring, anti-vaccine folks can now just tweet or post messages on Facebook. It is also relatively easy to self-publish an anti-vaccine book and sell it on Amazon, put up your own anti-vaccine website, post videos on YouTube, or even make movies.
“Whatever you think about Andrew Wakefield, the real villains of the MMR scandal are the media.”
Ben Goldacre on The MMR story that wasn’t
Fortunately, all of that is balanced by something they don’t have anymore.
No, it’s not science. That was never on their side.
It’s that the media has caught on to the damage they were doing and isn’t as likely to push vaccine scare stories anymore.
Explaining the Popularity of the Anti-Vaccine Movement
The anti-vaccine movement has always been around and they are likely not going anywhere, whether or not they are growing.
“By the 1930s… with the improvements in medical practice and the popular acceptance of the state and federal governments’ role in public health, the anti-vaccinationists slowly faded from view, and the movement collapsed.”
Martin Kaufman The American Anti-Vaccinations and Their Arguments
Why so many ups and downs?
It is easily explained once you understand the evolution of our immunization programs, which generally occurs in five stages:
pre-vaccine era or stage
increasing coverage stage – as more and more people get vaccinated and protected, you pass a crossover point, where people begin to forget just how bad the diseases really were, and you start to hear stories about “mild measles” and about how polio wasn’t that bad (it usually wasn’t if you didn’t get paralytic polio…)
loss of confidence stage – although vaccine side effects are about the same as they always were, they become a much bigger focus because you don’t see any of the mortality or morbidity from the diseases the vaccines are preventing. It is at this point that the anti-vaccine movement is able to be the most effective.
resumption of confidence stage – after the loss of confidence in stage three leads to a drop in vaccine coverage and more outbreaks of a vaccine-preventable disease, not surprisingly, more people understand that vaccines are in fact necessary and they get vaccinated again. It is at this point that the anti-vaccine movement is the least effective, as we saw after outbreaks of pertussis in the UK in the 1970s and measles more recently. You also see it when there is a report of an outbreak of meningococcal disease on a college campus or a child dying of the flu on the local news, etc.
eradication stage – until we get here, like we did when smallpox was eradicated, the anti-vaccine movement is able to cycle through stages two to four, with ups and downs in their popularity,
So the anti-vaccine movement is able to grow when they have the easiest time convincing you that the risks of vaccines (which are very small) are worse than the risks of the diseases they prevent (which are only small now, in most cases, because we vaccinate to keep these diseases away, but were life-threatening in the pre-vaccine era).
“As vaccine use increases and the incidence of vaccine-preventable diseases is reduced, vaccine-related adverse events become more prominent in vaccination decisions. Even unfounded safety concerns can lead to decreased vaccine acceptance and resurgence of vaccine-preventable diseases, as occurred in the 1970s and 1980s as a public reaction to allegations that the whole-cell pertussis vaccine caused encephalopathy and brain damage. Recent outbreaks of measles, mumps, and pertussis in the United States are important reminders of how immunization delays and refusals can result in resurgences of vaccine-preventable diseases.”
Paul Offit, MD on Vaccine Safety
Fortunately, most parents don’t buy into the propaganda of the anti-vaccine movement and don’t wait for an outbreak to get their kids vaccinated and protected. They understand that you can wait too long.
The bottom line – except for pockets of susceptibles and clusters of unvaccinated kids and adults, most people are vaccinated. If the anti-vaccine does grow, it eventually gets pulled back as more kids get sick.
What to Know about the Growing Anti-Vaccine Movement
Although they may have an easier time reaching more people on Twitter, Facebook, YouTube, and with Amazon, the overwhelming majority of parents vaccinate their kids and aren’t influenced by what some people think is a growing anti-vaccine movement.