Are we now in the second wave?

The last time the world faced a pandemic – called Spanish flu and caused by H1N1 influenza A virus – was in 1918 yet.  

“Lasting more than 12 months from spring 1918 to early summer 1919, it infected 500 million people – about a third of the world’s population at the time,” Wikipedia reported.  “The death toll is estimated to have been anywhere from 17 million to 50 million, and possibly as high as 100 million, making it one of the deadliest pandemics in human history.”

History records showed there were four waves of the 1918 flu pandemic.  The first wave had resembled typical flu epidemics; those most at risk were the sick and elderly, while younger, healthier people recovered easily.  

The second started by August and peaked by October.  More people died as the virus had mutated to a much more deadly form.  “The second wave was far more deadly,” Wikipedia reported.  

The third wave happened in January 1919.  “It was less severe than the second wave but still much more deadly than the initial first wave,” Wikipedia noted.  In spring 1920, fourth wave took pace but mortality rates were very low.

Now, the world is now facing another pandemic.  Called coronavirus disease 2019 (COVID-19), it is caused by SARS-CoV-2 as it is a distant cousin of the same virus that caused Severe Acute Respiratory Syndrome (SARS).

Last May 20, during the resumption of the Senate hearing on the government’s COVID-19 response, Senator Ramon “Bong” Revilla, Jr. asked Health Secretary Francisco Duque III about the government’s plan should the second wave of COVID-19 hit the country.

“Actually, we’re on the second wave” now, Duque replied and went on to explain: “’Yung first wave natin nag-umpisa, batay po ito sa ating mga batikang epidemiologist, na ang first wave natin happened sometime in January.”

Netizens were totally puzzled.  Dr. Maria Rosario Vergeire, undersecretary of health, explained that in technical or epidemiological terms, the Philippines is already in what is called second wave.  “The first wave was a minor one, with only 3 cases at its peak, happened in January,” referring to the three Chinese nationals from Wuhan.

For most Filipinos, what counts are major waves.  The peak was last March 31, where the country had 538 cases.  “We have been flattening the curve, in this current major wave, with the cases averaging 220 in 5 weeks,” Dr. Vergeire said.

“What is most important now is that we all do our part in preventing a second major wave, by practicing handwashing, physical distancing, proper cough etiquette, wearing of masks and regular disinfection,” the health official said.

Dr. Edsel Maurice T. Salvana, an internationally recognized infectious diseases specialist and molecular biologist at the University of the Philippines (UP) and the Philippine General Hospital, further explained in a feature that was published by Manila Bulletin.

“Most recently, there has been much debate about whether we are on our first or second ‘wave’ of cases,” wrote Dr. Salvana, who is the director of the Institute of Molecular Biology and Biotechnology at the National Institutes of Health at UP Manila. “From an epidemiologic perspective, a ‘wave’ has a ‘peak’ and so if you see multiple peaks on an epidemiologic curve, then that is a ‘wave.’”

Right now, the Philippines has two “peaks,” based on the current Philippine epidemiologic curve. 

“There was a tiny peak from January representing three cases from China, and there is the current wave which peaked 538 cases last March 31 and is still ongoing, but on the downtrend of about 200 to 300 cases per day,” Dr. Salvana explained.  “This needs to be seen also in the context of increasing testing capacity which has gone from 300 tests per day to 11,000 tests per day.

“So, we are really capturing more cases now but it hasn’t gone beyond the 538-case peak.  This means the curve was flattened.  By flattened, we mean that the daily case count is steady.  If it were going down, then the curve would be ‘falling.’ Since the ECQ (enhanced community quarantine) is not a perfect lockdown, we still expect some transmission to occur, but the growth of cases is not exponential and our healthcare system is not overwhelmed.”

According to Dr. Salvana, there was a four-week gap between the tiny “first wave” and the current “second wave.” He asked: “How do we know that there wasn’t hidden community transmission that we just weren’t capturing with testing?  Maybe the first and second waves are connected?”

Dr. Salvana admitted they’re not sure of it “but there was active testing of PUIs (people under investigations) at that time.” “Anything is possible,” he pointed out.  “We do have some whole genome data that suggests that while the ‘first wave’ was from travellers from Wuhan, the ‘second wave’ came at least partially by way of India.”

He, clarified, however that it doesn’t mean Indians brought the second wave to the country.  “It only means someone travelled from India and most likely got infected by a virus circulating there and brought it to the Philippines,” he wrote.  “We don’t know if the person was Indian, Filipino, or another nationality, only that he or she travelled from India to the Philippines.”

Looking at the 12 whole genome sequences from the Philippines that were collected in March, “these viruses all trace back to an Indian progenitor virus, which came to India from an Australian progenitor virus, which can be traced to a progenitor virus from China.

“The analysis is by no means complete,” Dr. Salvana wrote, “and we probably did have multiple introductions from the second wave but this is the evidence that we have at this time.” 

Although the analysis is not really exhaustive, due to the small number of available sequences, “it does give us an idea that the virus can come from anywhere,” he said.  “We cannot let our guard down and we need to limit transmission of the virus as much as possible.”

However, Dr. Anthony Leachon, an adviser to the Inter-Agency Task Force (IATF), told ABS-CBN Teleradyo the Philippines is still in the first wave of the COVID-19 pandemic.  “Ang first wave na alam ko ‘yung unang nag-lockdown, ‘yong community quarantine kasi ang doubling time nun mabilis,” he was quoted as saying.

As of now, the Philippines has not flattened the curve yet.  “We have not yet flattened the curve eh kasi ang second wave nangyari after na mag-flatten ka,” said Dr. Leachon, an internist who works at the Manila Doctors Hospital. “So parang ‘yan ay experience sa Spanish influenza ng 1918, nag-flat siya tapos tsaka ka nagkaroon ng second wave.” 

But whether we are still in “first wave” of the pandemic, or now in the “second wave,” it doesn’t really matter.  “Unless we get a vaccine, there will almost certain be another wave, and several more after that,” Dr. Salvana reminded.  “The wave we have to deal with is the next one.

“Whether the peak will be higher or lower than 538 cases a day will be determined by our ability to trace, test, and treat properly.  We are in a much better position to handle the next wave, with increased testing capacity, expanded isolation facilities, and intensified contract tracing.  Let’s hope for a gentle ripple and not a tsunami,” concluded Dr. Salvana, who has spoken and written extensively on the COVID-19 outbreak.

Meanwhile, in his opening remarks at the media briefing on COVID-19 last May 20, World Health Organization Director-General Dr. Tedros Adhanom Ghebreyesus said: “The pandemic has taught and informed many lessons: health is not a cost; it’s an investment.  To live in a secure world, guaranteeing quality health for all is not just the right choice; it’s the smart choice.”